Talk:Mercedes-Benz SLS AMG Coupé Black Series (Research & Development)/@comment-36912561-20181017133722

Three free upgrades. First one at test 3, lab1. Second one at 1st test of lab2, the 3rd one at the last test of lab2.

Refill time 3hrs.

At the 1st test, upgrades are blocked. After completing the 1st test they are all open and you can choose to upgrade to your hearts content & use the free upgrades for the costly ones.