Another one to share for anyone who has a child mad on planes or cars:http://www.brooklandsmuseum.com
We went on Sunday and it was great. The canteen is good and reasonably priced, there is a soft play area, you can take the Concorde experience (which is surprisingly emotional!) and have a tour around an actual Concorde. There is a bus museum, various planes including one they pulled out of Lock Ness, an educational room with various puzzles and exhibits aimed at kids, plus the worlds first purpose built racing track, lots of old cars and bikes as part of the exhibits in the various shed, plus various hangers with lots of stuff to do with building planes (Vickers was based there, they made parts of Concorde, Barnes Wallace was there, the bouncing bomb was developed there, they made Wellington Bombers etc.)
They have various events, we saw loads of old racing cars. Our son loved it.
It's about 1.5 hours away (a little less if you leave earlier on a sunday morning) by car.
Well worth a visit and very educational.
Tickets are £11, children under 5 are free.