Autoworld is one of the biggest collections in Europe. I think there are about 300 cars there. Mr Mahy who started collecting cars had at one point almost 1000 cars. There is a large warehouse somewhere in Belgium which has few hundreds cars waiting for restoration (I once saw pictures of this place).

Like Antoine says most of the cars are pre-WWII and if you like them it is a must-see place. The building alone is worth seeing and there is also a car book store inside the premises.