Thank you very much Nemiro, certainly didnt expect such a lengthy plus sincere response! Plus so much information to take in! Notes taken.

Just as you describe, the trust and rapor you establish with customers, it comes across very clearly in your response, your attention to detail, plus to please.
So many "outfits" these days are all about the profit. Shifting cars as fast as possible, and the time old attention to customer service, has gone out the window (no pun intended). Probably why alot of garages have a bad reputation (unhappy customers - sub standard cars).

I'll be honest, I don't have garage facilities, or access to any specialist tools. This would be literally a hobby for me. Plus I have to be careful how much I can take on. While a car that is spotless but has suffered an engine failure might be a bargain for someone, I simply don't have the resources or skill to take it on...

Sticking to one manufacturer / model is also great advice. Plus something I'm considering. We don't have so many exciting custom vehicles as you do in the States. It's all the routine mass produced German / Japanese / European cars over here!... VW, Audi, Mercedes, BMW, Ford, Vauxhall, Renault, Toyota etc...
Choosing popular runarounds might be cheap to buy plus put right, but as there's so many out there, also alot on the market for sale. Which could reduce profit margins, due to trying to stay competitive.

Are there any Sites you use or recommend, for used vehicle prices / buying vs selling? I suppose once you are familiar with a specific model, you better understand how much they are work (to buy and sell, plus how much funds you can put in, yet still pull out a worthy profit).

Again many thanks! Will keep you updated...