I spent ages looking, must have looked at about 5 or 6 but held out for exactly what i wanted at the right price. I found it was important to learn how to say no to salesmen, and pick up on every minor defect for bargaining, my car was up for ?4,750 (spent about ?70 putting these little things right). You soon pick up on the common faults though.
I had to travel about 60 miles at 8 o'clock one sunday night to meet the garage owner, he had someone coming on monday morning, had to do all the looking on a petrol station forecourt for some decent light. Great fun.
Luckily i was replacing a crashed car so had nothing to sell, although i did use my parents Toyota as a p/x! My advice is always write off a car the same weekend someone in your family buys a new car, it's really convenient!