London-Bath-Stonehenge, Windsor-Oxford - Car question

This is on your day of arrival? From overseas?

If you either pick up the car in Windsor or stay/sleep in Windsor, then the car rental agency or the hotel could probably hold your luggage. Or make an earlier pick up for the car and put the luggage in.

[edited] If you were coming from Heathrow, then you can make one connection at London Paddington station to reach Oxford but would need two connections or a bus to reach Windsor. Trains from central London run direct to either Windsor or Oxford in about an hour (but stations are different).

No we are spending 5 days in London first so will have adjusted to time/jet leg etc.

Windsor is a short drive from Heathrow, so after your time in London, pick up a rental at Heathrow and drive. Windsor to Bath should be around 2 hours. Stonehenge is southeast of Bath while Oxford is well northeast of it, so hopefully you don't want to visit all in the same day. If you see Windsor in the morning then drive to Stonehenge and see it in the afternoon, you could spend the night in Bath, but that's a lot for one day. Windsor is worth a full day by itself as is Bath. From Bath you could skip Oxford (unless there is something specific you want to see) and head towards Edinburgh via the Cotswolds. Overall it sounds like you still don't have a set itinerary. The route you take will be dictated by the itinerary.

Windsor has difficult and expensive parking. Difficult because there is virtually no street parking anywhere near the castle and expensive because if you find a space in one of the carparks they are expensive. On weekends you can park by the Riverside station for a moderate price and reasonable availability if you are early.

Be aware that the 15 and 12 year olds are eligible for child tickets (ages 5-15 inclusive) on trains, and you can save even more if you invest £30 in a Family and Friends railcard.

Consider train from London (Waterloo) to Salisbury and check into a hotel. Then take shuttle bus out to Stonehenge. See Salisbury cathedral. Next day, train to Bath - another place with difficult parking. Check into a hotel - ideally within walking distance of the station.Then, consider renting a car to head wherever - possibly Cotswolds first/or/ continue to use trains to eventually end up in Edinburgh / or/ fly from Bristol to Edinburgh. www.skyscanner.net

If using trains - get a family railcard and pre-book longer trips ideally 11 weeks out for lowest prices. www.nationalrail.co.uk

Windsor is within the London commuter belt. Wait for the crowds to thin then do it as a day trip from your London base. If you use the 09:50, 10:50 etc. train it's a 27 minute journey from London PADDINGTON station (change at Slough). The "OFF PEAK DAY RETURN" (round trip) fare is £10.80 (£5.40 for each of the kids). More expensive if you travel earlier on Monday-Fridays. The return journey is slightly slower with a longer wait at Slough. There are direct trains from London Waterloo but they take much longer and cost slightly more. Use the nationalrail link given above for detailed times, search from PAD to WNC and click Add Return Journey (or it will only show expensive one way fares). If your hotel is within a short walk of Waterloo you could use the other route from WAT to WNR.

As for rental cars, don't forget that if it doesn't specifically say Automatic in the description it will have a manual gear shift!