Lotus is way out in the middle of nowhere in Norwich. But a super place, with a good guided tour. Huge Lotus dealership in Warwick, with a TVR dealer in the same complex. Very nice collection of cars between them.
Near Bournemouth in Beaulieu is the Lord Montague museum with some awesome cars. Lots of the very old (19th century and the like), but some modern F1 cars, a real GT40 and Jag xj220. Saw my first Evo5 and sti there in the parking lot (years ago).