Car cleanliness affect CarMax price?

Trying to sell my car via CarMax, it's in excellent condition, but it's been in a garage for a year, so it's got a coating of dust on it and just the usual light dirt on and around the floormats.

I've heard stories of getting a $200 detail resulting in $1000 more on the offer to buy in some cases. Anyone who used CarMax know if the cleanliness affects the final offer price, or they overlook cleanable cosmetics for engine issues or non-hideable damage?