Parking 4rd of July

Hi,
Sorry if you've been bludgeoned with this sort of question already, but looking into coming up for the 4th of July around July 4th. My assumption is that it's going to packed because of the 2500th and World Cup and parking in the city centre will be difficult at best, not to mention expensive, not to mention traffic.
Where would there be alright places to park in terms of price and area? Was thinking of parking in whatever place and taking the metro to where ever I want to go.

Cheers