My manager just bought a used car (practically new, under 30k miles) and I couldn't possibly remember to recount all the different things he told me. He's probably one of the smartest shoppers I know, and it was no different in this case. He went to dozens of dealerships over many weeks as he searched. Probably one of the most important things he told me is this: always remember that there are more cars like it out there and there will always be. He was closed on many many times and never bought until he was absolutely positive. Just like you, he had a price range going in and he stuck to it and that's a very good thing.
Another thing he learned is NEVER go into a dealership without an appointment with a salesperson already set. And, when setting that appointment, what he did was call the delaership and spoke to the receptionist - who is more likely than not unbiased - and asked to speak to the most experienced and nicest sales rep they have. That's who he set up appointments with and since he started doing that he very rarely had a bad experience at the dealerships.
He also always asked the sales reps questions such as 'how long have you been working here?" What he found was that the average length a car salesperson spends at a dealership is 3 months. That's not enough to learn ANYTHING - about cars OR being a good sales rep. So, he always dealt with people who had been around for awhile - the best people he dealt with tended to have been with the dealership for over 10 years. There was a guy at a BMW dealership he went to (out of his price range but why not look

) that had been there for 30 years - and it showed. The amazing thing is that he had been at that dealership the shortest of all the sales reps there.
As far as the sales reps he got like the one you experienced - before he started asking all these questions - he'd let the management know how he felt and a lot of times when he went back to the dealership those sales reps were no longer there
One thing I know personally is that I'm glad I have a good relationship with my manager, cause when I get a car there's no way I'm doing it without consulting with him.