One tidbit of advice I can offer for those who are driving a decent distance for the fest would be to tape off your front end. For me the worst part of cleaning is trying to get all the bugs off. So what I've done in the past is simply go to Lowes or any similar store and buy a roll of blue painters tape. Tape off your front end, including mirrors and front of hood. Then when you get to the fest simply peel it off and voila, clean front end without the need to scrub off any bugs to massacred along the way. This works well for the ones who are kinda finicky about using pressure washers on their car. There is however a car wash about a mile from the track so that option is easily within reach as well.
Using the tape method is also great to protect against rock chips that you might collect along the way for the trip.
Hopefully this helps.