Many kids that I age that I know (teach preschool) are afraid of most of the things you mentioned.... bouncy houses (big, noisy, squishy/wierd to walk on makes you feel like you're falling), car wash (noisy and can't see out windows), costumed people (thousands of kids at Disneyworld freak out daily when they see a giant Mickey coming at them!), etc. My 7 year old wouldn't get near a bouncy house until he was almost 6, my 2 year old screams and runs away from them. My 4 year old is terrified of the car wash.
My 2 year old loves bubble baths with her 4 year old sister but she >hates< having bubbles cling to her hands. Go figure.
Keep exposing her to some things, but be nice about it. If you know she hates the carwash, simply don't visit one with her until she's older. Ditto with bouncy house places. If you see one at a party, she's exposed to it and watching other kids go in/out, but don't press her to do it. No need to force some things, these really aren't big issues and they'll more than likely go away with time.