pressing start brings up your info panel, includes ghosts killed, ash collected and health. And you just didn't have enough Ash. As for the driving, speeding it up felt more off then slower. I messed with it for awhile and that's where I liked it.
It wasn't any easier to see the Ash if I put the vac behind. I had it behind but it looked off and you couldnt hardly tell the vac was on. It was just the ground being the same color. Boss ash is harder to see. Ha