I got my car from Carizma, service was really good, the price was really good they seemed to be very negotiable on the day if you know what your talking about.
Nothing dodgey on the car that ive noticed, and most of the cars are in good nick, they also offer 12month warranty, and 24hr gold road side assist, as well as discounts on parts etc from thier shop with all sales.
Theyve been in business for a good 10 years I beleive, so they seem to be pretty reputable, I havent heard to many kill stories from them.