“Peanut butter inside” is a saying the rappers often use in songs, (Kendrick Lamar, Swae Lee) discribing that the inside of their car is brown or a brownish color. The car is Peanut butter inside.
Tanner: “hello friend, what color is the inside of your car?”
Trevontarious: “mannnnnn... that bihhhh peanut butter inside!”
"inside peanut butter outside jelly" refers to having a tan/brown leather or plush interior in your vehicle, with a (metallic)candy paint job on the exterior. (These color schemes are commonly used on Lowriders or American Muscle Cars, such as Cheverolets.)
Inside peanut butter outside jelly 7 days of the week 7 different chevys
Black SS wit tha top blown off
f*** with them boys get ya top blown off