When I last bought a car, I found the AA's website useful. You could do comparisons between different ones and I assumed that their opinions were probably unbiased. But be warned - if you put AA into google you sometimes get the site for those who like too much !
Ah, but they have done all sorts of research that shows that car purchasing decisions are made for reasons other than practical ones like looking at the specs and knowing the price.
The only problem is that people like you, Mishap, and I want information not advertising meant to reach us emotionally. I once chose a washing machine on the basis that it had an advert that gave me clear info on the machine and its features while the other I was interested in and thought might be more suitable failed to give me any info at all just a lot of photos of the machine taken from funny angles and a lot of puff.
I am researching buying an automatic car and went onto the Honda website. It nearly drove me nuts! - pictures and information hurtle past on the screen without giving you time to read what it says - grrrr! I just wanted to know the specs and how much they are!