Nice idea for a combination of idle and racing. Nice clean art and interface.
I feel like there isn't enough that actually makes the income much faster and all upgrades don't accellerate the progression enough to keep the player engaged. The thing about it not running in the background is a real shame but I guess after the jam you can fix that very easily. I'd highly encourage making progression faster and including some mechanic that actually increases the funds you get. Maybe you can style your car somehow and the people give you more money for that or so... Idk I think it has a lot of potential for fun but the balancing doesn't really make it all click at the moment.