you have a LOT of problems with your variables. Cars resale at 2-3 times their original values. Also I don't think you mean us to be able to buy each upgrade 4 or 5 times, I have a 619 Bhp 942Kg eclipse that I earned the money for by repeatedly buying and selling vehicles
5/5 I miss turn based gaming. The only thing I would like to see is an undo function. It might lower the overall difficulty, but it would allow for multiple attempts at coming up with novel ways of winning.
Not bad, but strategy comes down to click all of a color as fast as you can, find the first number that matches the last one you clicked on that you see, repeat. It'd make the game slightly harder if multiplier dropped as you clicked the same color than raised.