Sorry I haven't been checking in here for 6 or so months. There is a HUGE array of 1/43 models out there, diecast, hand builts and kits. If you're looking to keep in scale with your 1/48th aircraft try
www.matadormodels.co.uk (plenty of 1/48th trucks etc) and
www.grandprixmodels.co.uk although the latter is race/rally focused they do have a huge selection of road cars from all era's but generally 1/43 rather than 1/48th. You could also civilianise some of Tamiya's and other's 1/48th military cars/trucks
Kia ora,
Mark
"Time flies like the wind, fruit flies like bananas"