Given the following context:

Jim works as a car mechanic with Jerry on a car for Keller which turns out to be bulletproof. One night while Keller and his gang buy champagne from a convenience store, Jim arrives using Keller's car robs the convenience store. However, as Jim was about to flee in Keller's car a police car arrives. The officer aims his gun at Jim demanding him to get out the car and opens fire on him. But the bullets are not effective on the windshield and Jim taunts the officer and drives away. Another police car attempts to corner him, but he easily overtakes it and escapes. The next day Jim is then confronted by Keller and his gang about the incident the night before. They order him to bring the bulletproof car to his house. After Keller and his gang left, Jerry lectures him as he was about to deliver Keller's car. While on the way, Jim stops at a car wash where he meets Gem and she's being led away by her boyfriend. Jim finally arrives at Keller's house and hands Keller the keys of his car and orders him to get the Ferrari 328 GTS from a couple in the mountains.

answer the following question:

Who backs up Keller's demand that Jim deliver his car? 

his gang