Its all in the car the bob gets (except maybe NASCAR).
I don't really mind because I use remote racing in the opposite way you do. I see it as a way to give, not to get. I use it to help my friends and if I get a little bit along the way, its an added bonus. I have also logged in to find that someone has been remote racing my bobs in return and have also received some gifts from friends for doing it (Speed 12 with all tuning parts and tires). But, even if I didn't get anything in return I would still do it to help out my friends, especially those with level 0 bobs. And I would hope they get the win every time.