You can look for some incar-footage on websites like youtube, google-video and the likes of them and compare them to the GT4/Enthusia counterparts, at least that's what I do. TopGear also has lots of sound-coverage and the BBC has decided to put more of their coverage online, check out their website at www.bbc2.co.uk/topgear .JohnBM01I still find it hard to actually judge what it is we're judging on in terms of accuracy in sounds. I think the GT4 crew was talking about taking sound samples from certain cars in some place. I don't really know how accurate things actually are for GT4 or Enthusia. So I don't know much on the sound front.
Of course, if it's youtube (and the likes of them) the engine sounds suffer a bit from cheap recording/bad sound-quality, but you can tell in an instant where PD couldn't get the real sound (for whatever reason) and sometimes there are good samples around which can be compared to the games.
Best Motoring (apparently lots of their stuff had to be taken off due to copyright infringements) was a good source for japanese cars ...
And I'm still impressed that Konami bothered to include that sound which reminds you to shift in the Mazda rotarys.