Hello mate If you drive past the ground on the A1134 Newmarket Road (heading east with the ground on your right), turn right into Whitehill Road. This takes you into an estate, and you should be able to find free parking on one of these roads (eg Stanesfield Road). I'll be parking in that area. Enjoy the game!
There is loads of street parking further up Newmarket Road (past the ground coming from the city centre). They don't get huge crowds (impossible in their ground) so it shouldn't be a problem. I think parking in the city is a massive problem these days so they've put in quite a few facilities to stop you needing to drive in, including the guided bus route from the north which has a park and ride site out near Longstanton just off the A14. So if you're concerned about finding somewhere closer, I'd recommend that. Also there is a low emission zone so probably best all round to use the park and ride.
Just watched the Recap video and it looks like they have built a proper stand at the away end with seats.....