First car I bought was a beater from an individual. Never needed an oil change, just a filter change. Adding a quart every 1k miles kept that part of it fresh. It lasted me enough years to where I could afford a new car. I bought my first new car through a broker. Someone I worked with recommended the guy, so I called to see how it worked - I tell him exactly what I want (all colors, options, whatever) and he calls back a week later and tells me a price and pickup location, time, and date. Take it or leave it. That worked out just fine.
Worst experience was when I was looking for a car to replace that first new car - first car wasn't family friendly, and we had a baby on the way. I went to my local credit union to ask about car loan rates and they pulled out a sheet and said, "Hey, look! The local XYZ dealer is having a "credit union" special. They guarantee a price (can't remember if was below invoice or whatever, but it was a pretty good deal) and it goes into effect at the beginning of next month." I went to the dealer the next day and worked out a pretty fair deal on my trade, then said I wanted to get into that credit union sale a couple weeks early. They got pretty angry that I knew about it ahead of time and actually started yelling at me about it, then changed the deal on my trade. I walked out. The next day I went to a different dealer in town and got the deal the first one wouldn't do. The day after THAT, the first dealer called me back and wanted to know if I would come back in to talk again - too late.
The last car I bought I ended up talking with the salesman for a while. Somehow we got to talking about flying, his dad's a pilot, so the guy tossed in a few extras for me. Whenever I stop in for parts or whatever, I always swing by that guy's desk to say hi.
Other than that, most of my car buying has been just something that I want to get over with as quickly as possible.