The car rented by the CIA agent was rented by Universal Exports. Universal Exports was the company that James Bond used as his cover when he was undercover.
The meaning of the title comes from the British meaning of the word "boot", which is what they call the trunk of a car. They call the front end the bonnet.
When the corpse is discovered in the trunk of the Aston Martin you can hear a homage to the James Bond theme song playing.
The book Hodgins refers to over the cat excrement is "Everyone Poops" by Tami Gomi
The Aston Martin paint color is Casino Royale. Casino Royale is the name of the first novel written by Ian Fleming. Ian Fleming created the character James Bond, the gentleman spy.