GamesDomain have posted their first impressions on Grand Prix 3, and so far they seem to think the game is quite good.
They will have a full review soon, but you can see their first impressions by clicking here.
Axel in the forums posted that PC-GAMER (UK PC-games magazine) gave Grand Prix 3 an 8 page spread and gave it a score of 95%. That compares well to GameSpot's 97% score I posted about yesterday! You can buy the magazine in most local stores.