Help with driving itinerary with south west England?

To be honest, you could spend a week in Cornwall & Devon and not see it all - same with Wales. Castles, stately homes, gardens as well as scenic areas are just about everywhere.

Cornwall is not listed & neither is west Devon - but more or less in order of your trip will be :> Wiltshire, Dorset, Devon SE, Exmoor, Somerset, Bath (I would skip Bristol), Wye Valley (lower), Cardiff, Brecon Beacons National Park, Wales - Mid, Wales - north, Shropshire, Herefordshire, Gloucestershire (Cotswolds), Birmingham (for Stratford-upon-Avon), Oxfordshire.

If you click on a photo, you will see a little map where you can zoom out to figure out where it is.
Don't forget that Wales has its own forum.
Also check out the official tourist board sites that usually begin www.visit ---- .com or .co.uk (some commercial organisations might also use one or the other).
So, Wales for example is http://www.visitwales.com

If you book hotels in city centers, parking can be limited or expensive. Trains = www.nationalrail.co.uk (Pay on the day is dearer for journeys of say over 1 hour. Tickets are cheaper if booked ahead - even the day before but this might mean you must use specific trains).

Personally, I would not hire at Heathrow, but take a National Express coach westwards and hire at any largish town that you decide on as your starting-point. That way you can rest a little while still leg-lagged and not have to cope with LH drive in the traffic snarl around Heathrow.

many thanks for the information, we will investigate. we have no problems with hiring a car, as we will be arriving into london by train from brussels and live in australia, so not a major issue. although we don't want to hire in london itself. so heathrow seemed logical?

If you are arriving in London by train, Heathrow is a red herring. What is your first overnight outside London? take a train there (or to the nearest railhead), and pick up the hire car there.

after looking into car hire companies, it appears that it is 'easier' to pick up at Heathrow, ( makes sense eg: 24/7 operation ) and many different companies to choose from. also we know how to get from our accom in London to Heathrow, so seems logical. and then head southwest.
we are interested in ideas of where to stay on our first night (and subsequent) nights out of London?

"We are use to driving on the 'left' and large distances."

You may be used to "large distances" but you can't really compare our roads with Australia's (ours can get snarled up easily, road works, accidents, sheer wait of trafic etc).

Others can correct me on this, but aren't there restrictions on cars in Central London? My advice still stands; take the train west from Paddington, or a National Express coach from Victoria, and hire when you get to your preferred starting point. Cut out one day of car hire costs, and minimize the time spent driving on soulless motorways.

Here is a good site for finding car hire companies - anywhere - not just at the airport. (Check that the car can be returned to a different location).http://www.travelsupermarket.com/c/cheap-car-hire/

So, we now have a bit more info about your trip & that you are not landing at Heathrow. From what you say, it sounds like you wish to see Jane Austen "places" . If you leave London, heading SW on the A31, head for Alton and the village of Chawton. See>
http://www.jane-austens-house-museum.org.uk (This is shown under 'Hampshire' on the photo site I gave previously).

Having done Chawton, I would next head for Winchester - see cathedral etc. From Winchester - take B3049 going NW & then A30 to Salisbury (for 1st overnight).

Next day would be the short drive N to Stonehenge. From here, you can follow the A303 & A30 all the way to Exeter. However, mid way, at junction with A3088, you might like to make the short detour to see Montacute.http://www.nationaltrust.org.uk/montacute-house/

I suggest that you try and follow the intended routes on Google Earth.

hello James many thanks for keeping on topic many thanks for the information, yes i believe that there can be extra for dropping off at a different location ( hence why we were thinking of pick up and drop off at the same spot close-ish to london but hopefully outside any 'traffic' zones) we have not had enough time to see all of your photos, but intent to view more.

while we are interested in jane austen we would like to see many other things. perhaps not too many churches and castles ( seen plenty in previous travels, if you know what i mean) we were wondering if to see stonehenge and/or avebury when we come back up toward bath ( from port issac area) but your plan sounds good. can i assume it is a better option than seeing any of the south coast ( not that we have any reason to go there) also is there anything in particular to see on the leg over to port issac. eg: do we allow an extra night to see things or just drive there and then look around?
i realise its a difficult thing to answer, but with limited time, planning often has to be 'ruthless'. especially if there is potentially something better further on?

My guess is that you have Port Isaac in mind due to Dr.Martin? Anyway, if you are a Downton Abbey fan, Highclere Castle (where it is filmed externally), is just a 20 minute drive N of Winchester (A34).

You ask about the south coast. I don't rate the south coast east of Southampton very highly. If you are into naval ships, you may wish to visit Portsmouth Harbour.

Returning to my earlier suggestion of Stonehenge: you may wish to visit Avebury but it is quite a way to the north and in my view not worth going that far out of your way. However, it is worth going from south Wiltshire if you combine it with Bath instead of going to Bath on the run from Cornwall to Wales. If you are really into prehistoric stuff, when in Cardiff take the short drive west to St.Nicholas (A48) & then down the country road to Dyffryn Gardens. On the way to Dyffryn, you will see a place to pull in on the right and from here you can walk across a couple of fields to the Tinkinswood Burial Chamber. On leaving Dyffryn Gardens (should you visit), turn hard right and at the T junction - left. Park just around the bend and walk through the gate to the St.Lythans Burial Chamber. (If you just want to do one quickly - do the St.Lythans. (Find it in the photos of Cardiff).

Now back to the A303 going W form Stonehenge. Find a place called Stourton - just N of the A303. Here you will find the landscape gardens of Stourhead. They are great in late May and early June as well as end of October. Otherwise, lakes with trees and classical temples might not rock your boat. http://www.nationaltrust.org.uk/stourhead/

You recall that I mentioned Montacute. You could continue from here south to the coast at Lyme Regis - which has connections with Jane Austin.http://www.lymeregis.org/jane-austen/ You would then use the A3052 to reach Exeter but Beer is worth a detour.

Exeter can be difficult - traffic wise so I would suggest you shoot around it on the motorway. 2 routes go from Exeter to Cornwall. Go one way on the A38 and perhaps back east on A30. I would skip Dartrmoor as far better upland scenery exists in Wales. Totnes, Dartmouth & Salcombe are all nice places in south Devon but you would have to add a day so maybe best for you to skip these places. Avoid Torquay & Paignton = congested & far better places exist.

In Cornwall, these places are worth a visit:> Looe, Polperro, Fowey - combine with http://www.edenproject.com,
Falmouth - combine with http://www.trebahgarden.co.uk & maybe http://www.nationaltrust.org.uk/glendurgan-garden/;
Marazion - to look across at St.Michael's Mount, The Minac Theatre (cut into cliffs) near Porthcurno, Land's End - though rather commercialised, St.Ives, Padstow. I have not been to Port Isaac to Tintagel. http://www.visitcornwall.com

You might be better off with a base in central Cornwall - maybe near Truro. www.travelodge.co.uk & www.premierinn.co.uk have places with parking in Cornwall. Alternatively, you could try >http://www.farmstay.co.uk
www.booking.com
For hotels, this site might come up with the best deals:>http://www.hotelscombined.co.uk

This site will give you distances & timings. http://www.theaa.com/route-planner/index.jsp

Truro to Bristol/Severn Bridge takes just under 3 hours going non stop & using the expressways. If you use the A39 route via Exmoor - it will take considerably longer. If going to the lower Wye Valley (Tintern etc), you should cross the Severn on the M48 bridge. If going direct to Cardiff, use the M49 & M4 bridge.

Make sure that you have bookmarked the site with the photos and noted the order for your trip.

Just to comment on the Heathrow rental..... On our first trip to England a year ago, we rented a car at Heathrow and drove out of there just fine, only hitting the curb a couple of times on the passenger side. If we bumbling Americans can do it, you will have no trouble!
Of the area you're considering, we went to Bath (found Rick's recommended Apple Tree B&B just fine; it was lovely and convenient) and Avebury (be sure to take a tour of the stones and visit the BBC-renovated home). One recommendation is to purchase a National Trust membership and thereafter target those sites. It was a marvelous budget saver and compelled us to see lots of wonderful historic places.

Thanks James, once again a mountain of useful information. i will investigate. thank you for take so much time putting this together.
yes we are heading to Port Issac area as we have watched Doc martin. we find that TV shows and movie locations ( that we like) are a good way to create a 'skeleton' of things to see, then add extra places/things on top. we can relate to the location and you need a starting point for planning.
Glenn