Iv worked in main dealers for years in Sales and here's my view. As mentioned if the car is in warranty still it's very difficult to sell for what a lot of people assume they can if not got approved dealer service history. A car is only worth what the market will pay and the market will pay more for a dealer stamped book. Once a car is out of warranty as long as it's got a provable history with VAT registered garage not a big issue although full dealer history is a nice plus so could help the car sell quicker.
With special(ish) cars I would suggest a specialist history is better than a main dealer history. Iv got an edition 30 and to be quite honest I wouldn't trust a dealer to touch it. Find a good Indy and stick with them. At a dealer it's very unlikely the same person will work on your car and they are under pressure to do a 3 hour job as quickly as possible where as a good Indy you can form a working relationship and their name is more important than selling hours. Bit of a blanket statement as I'm sure there are some great main dealers and some bad Indy's but not normally the case.
As also mentioned as our cars are getting older they attract enthusiasts rather than your normal car buyer and imvho a specialist history is worth more than a dealer one.
