High heat races rewards?

Hey all,

Quick question here.

For the ultimate and ultimate+ parts it says you need to unlock em with high heat races.

Now i am not at 50 at the moment (still at 35) but ive completed 2 high heat races so far, which gave me the pink parts icon on the minimap.

So my guess is here, that i should drive to a safe house asap while having that pink icon on my minimap to get it "banked" so to say.

It is indeed gone from my minimap when i enter the garage and exit again, however..

Its not shown in my parts list when i want to upgrade the engine, tires, weight differential, etc etc.

So, the 2 parts that i brought home, will they only unlock when i hit rep level 50 or something like that?

Or shouldnt i bring them to a garage or safe house, but to a parts shop, or even a dealer instead?

Thanks in advance for helping me out with this.

Cheers, Mara