Frankfurt is a big party town for New Year's Eve, and the banks of the Main river have the best view for the fireworks at midnight apparently. Don't forget to bring a bottle of champagne to celebrate ;-)
Don't know about the parking over there (others might answer, and in any case please report back ;-) ) but in the worse case scenario you can always park the car close and join the very centre by public transport.

 

Wahoooooo carrément impressionnant ! Mieux que Londres pour l'an 2000 !

Pour l'occasion, je rappelle que vous pouvez uploader les photos sur l'espace Flickr d'EasyExpat: http://www.flickr.com/groups/easyexpat/