I loved the idea of specialising in a brand or type of car but these days it scares me off.
Suppose you specialised in diesels - recently you're screwed.
Estates specialist - SUV's have killed that market for me.
Prestige - Takes a certain person....I can't handle the big ego but instant HP decline brigade.
We thought about autos because there's a huge demand locally but try buying one without a knackered box in the block.
Bog standard risk spreading is best for me...at least that way I have one of every un-sellable motor rather than a forecourt full of the same unsellable ones.