Man I laugh every time I see the civic racing the porsche. I think the firebird V6 they ride in to steal the porsche would be a better match for the F1 civic
As far as the BMW and the crown vics keeping up with the 500...I don't think the 500 was all that fast in stock form. I don't know what kind of mods they have on it but I do know they have a special suspension and steering rack on it to let it handle like it does. It does have an exhaust and cam for sure. They had like 7 of them too.
Watch the speedo in the movie though. It is like totally off when he is accelerating. it takes him forever to get up to 100 and then he hits the nitrous and does this knight rider turbo boost up to 200 mph or something and leaves sight of the helicopter lol.