1) A raised flat portion of a sedan or coupe that is usually located behind the second row of seats. The rear shelf is on the same level as the trunk of a car making items placed upon them visible through the vehicle's rear window.

2) Someone with such a huge fat ass that you can place items on, for instance the entire Encyclopedia Britannica.

(noun) A successful type of theft which results in an acceptable, impressive and rewarding payday for the protagonist.