I can highly recommend The Shine Factory (he is based in Swindon). Had him out a year ago for a claying, 2 stage machine polish and wax on my Z3. 9 hours of solid work on my driveway, and left the car immaculate.
Final thing was a coat of Zaino something or other that stops the dirt from sticking to the car. For about 2 months I didn't need to use any soap on the car when washing it.
Will be calling him to give my MINI a detail before selling her.
p.s. I'm a newbie waiting to collect his Z4 next week...