Car trip through England

I've done it twice. In 2006 from London to Brighton taking all backroads ( didnt drive) and last year I rented a car in downtown London (I dont recommend that) and drove all over the Cotswold area for a few days.

My mom and I rented a car in Sept '07 & drove from Bath to the Cotswolds then down to Hampshire (then to Gatwick, which was very stressful & confusing). I did all the drving for 6-7 days. To tell you the truth, even though I did very well drving, it was stressful leaving Bath and trying to find our B&B in the Cotswolds. It was convenient, though, to have a little car in Hampshire (Jane Austen sites).
If you've never been to England, I would recommend going to Bath first by train or bus. There are many antique stores, gardens & wonderful B&Bs. The Cotswolds are not to be missed, either, and have antique stores/gardens. If I had it to do over again, I'd have us take a bus up there, too, then hire a taxi to drive us around to the villages or go w/a tour group. If you can, DO WALK from village to village. It's stressful/tiring driving long distances. Taking a bus or train down to Hampshire would probably have been better than driving.
It's beautiful country; you should go(continued)...

(cont): It saved time having a car and we had freedom but it was expensive (super CDW). I'd take public trans from each major spot but either hire a taxi or rent a car locally (to explore the towns/villages). Avoid driving yourself to/fro any airport.
Not sure what kind of gardens you are interested in but there are tours for many big ones. I would definitely recommend B and Bs or boutique hotels but in Hampshire, the Swan Hotel (Alton) was very historical. I could give you recommendations for Bath or the Cotswolds if you'd like. I love it there and am going back...
There never seemed to be a shortage of Antiques, gardens or good B and Bs anywhere we went.

We did 3 weeks driving in England in 2001. Drove from London to Canterbury, saw Dover castle, Leeds castle, then drove to the Devon area. Had a self-catering unit for a few nights - rode bikes, visited Lyme Regis, Chesil Beach. Then drove all the way to Cornwall which as fabulous. Saw Mount Saint Michael, Tintagel Castle (where King Arthur was "born"), took surfing lessons, went to Lands End, etc. Then had 2 more self catering - one outside Bath, one in the Cotswolds. Loved driving all the villages, seeing sites both big and small. Finally drove to North Wales, seeing Edwards castles, at least 3 of the 5. All in all it was a fabulous trip.

I understand that the gardens at Portmeirion are fabulous and you also might be interested in the Eden project and many other gardens in Cornwall. I highly recommend that area for off the beaten path- We met lots of Brits on holiday but few Americans. Same in North Wales - had folks buy us drinks just because we were visiting!

We have now done 3 different driving trips in the Engish countryside. For some great Bed and Breakfast recommentdation check out www.Karenbrown.com - they have great B&B recomendations all over England. My husband goes to our local Borders book store and bought one for our first trip. We have also used her books for France, Italy, and Washington state. Our first trip after spending time in London, we went back to the airport and rented a car to drive to Stowe-in-the-wold in the Cotwolds. It is a beautiful area. We did some driving from there and took the medieval walkway to Upper and Lower Slaughter and back. Our second trip we flew into Manchester and then drove up into Wales and rented a canal boat and then drove up North to Hadrians Wall and across to Robin Hood's bay and then back to Manchester. Our 3rd trip we stayed in London 3 nights and then rented a car again from the airport and drove west almost as far as Lands End. Each area has a different charm of it own.

(continued) We've stayed in thatched roof cottages, working farms, 15th century homes, lodges, manor homes, horse farm, etc. The owners of the small bed and breakfast for the most part seem so helpful with maps and books and recommendations of what not to miss when we are in their areas. The other people staying in the B&B seem eager to share their travel experiences over breakfast. On our trip to the Costwolds, my husband saw a sign saying Roman Ruins. He stopped and explored. It was very beautiful and we had the whole place to ourselves. Some of the roads look like oneway road or alleys. We were on one road that was a dirt road and had to wait until the farmer got his cows across the road. I told my husband it could not be a REAL road, but it was. I'd recommend spending at least 2 or 3 nights in the B&B you choose, and use that place to explore by car and by walking.