I wanted to start a thread about these jokers so others avoid my mistake. Kayak showed a rental via carrental8.com at about half the price of any other rentals (as a "surprise agency", so I booked it. It turns out it was booked with Fox, which I didn't want and didn't think was listed on their "trusted rental partners". I emailed CarRental8.com (the only way to contact them apparently) asking to cancel the reservation and whether they would waive the $40 fee for cancellation since I canceled right away, not wanting to book with Fox. They never responded despite my emailing them 3 times. I eventually just used the website to cancel the reservation and ate the $40. I'm considering disputing the charge with Chase, though it really was my fault I suppose.

Anyway, if you do book with carrental8.com, be aware that their customer service seems nonexistent.