Don't forget about checking rates with Undercover Tourist if you have bought tickets with them! It was showing rates for us in the $400's currently on Costco but
UT has rates of that are as cheap as $215 for our dates (for a go kart

, $269 for the Intermediate with
Avis I chose) . I was looking at the Hilton in DS because we are staying at SSR and could walk over in the morning and grab the car ($230 for Intermediate, Avis) but my BFF was the voice of reason and reminded me to pay a little more for convenience. LOL...
I bought our tickets with UT a few weeks ago and emailed them last night and they sent back a link that activated the low price. The other option is to buy a cheap ticket (they sell some Nascar thing for like $10 bucks-- or the theater popcorn ticket for like $5 but that only works when the theaters are open).