In the world of custom die-cast 1:64-scale toy cars, enthusiast builders replicate most of the cosmetic stuff people do to full-size vehicles—swap wheels, repaint shells, widen tracks, extend fenders, ...

Most car enthusiasts these days own one or two cars. But you'll occasionally see people with up to 10 vehicles in their garages. Sure, they might all be worth less than $100K put together, but that ...