Stuck in Supercow

I'm stuck in Stage 10, level 2 of Supercow. The goal is to find the exit, and I've been all over several times and can't find it! I'm tired of riding up and down on the rusty elevators. Any clues from anyone who has finished the game? And why have the mushrooms changed from friendly to diabolical-looking?

I wish I could help you but I am stuck at level 10-1 when I find an answer I will post it.