Sounds like UK car salesmen have been taking lessons from their US counterparts. That is a totally normal experience here. I'm not sure about the pricing but I am always concerned with a vehicle that presents with a coolant leak. I wonder how long that has been going on & have their been overheating issues.

Yellow is the best color for sure but don't take a lesser car just because you are chasing the best color. There is an old saying in the car business that the wrong car always costs too much. I did have to replace the top on my yellow roadster and it was $2k. I was lucky to find the top too. I know tops are a little easier to come by now because there was a recall on some of them but it is still a nightmare if the rear window falls in.

Good luck to you in your search - you are looking for the right color.