Dealership experiences:
Last time I was looking for a hatchback, the big brands here (Ford, VW, Chevrolet and FIAT) were all as expected, letting me test-drive a car for a few kilometers with the salesmen seating beside me on a pre-determined route. FIAT was the only one that let me drive the exact car I was looking for and not something similar, and that helped me decide about getting the Palio.
A few years ago, I went with my mother-in-law to a Chevrolet dealership and the salesman didn't even stop reading his newspaper before telling us: "We're low on inventory. Come back next week." What the fuck?
Renault was very good providing a car for a test drive (a Clio) but tried screwing me over when it was time to close the deal. In general, they know next to nothing apart from BRAND NEW STICKERS, MORE FUEL ECONOMY, BEST IN CLASS. Don't bother discussing technical specs.
Randomly visiting "luxury" dealerships was a surprise.
The BMW saleswoman knew EVERYTHING about the brand and the cars. She even took me to the lot to show me the 130i, which was new at the time. Surprisingly, it was the best service I ever had at a dealership, even though I clearly had no money for one and was just wasting time there.
Volvo guy was very clinical. Clearly sticking to a script, but treated me well.
I've never been to the Porsche dealership, although they have a Carrera GT for sale, so maybe I should.