Hiya Ben
Hey mate,why dont you give us an idea of what cars you are looking for?I have a bit of a stash of sites for the older car.Some very obscure (shut it Coxy!
),and some which just sell rare and pristine examples.
You could do worse that to try,for example Daniel Curnock at the 80s Emporium.
www.danielcurnock.co.uk
Not sure if he can source you an E30 but a good read!!
If you like pre-94 (or proper) Mercedes,try
www.bygonemercedes.com
OK,gimme what ya got matey!