There's an adult version of Little Tikes' Cozy Coupe that is street legal and goes up to 70mph.  It's even gained.

Remember having the little red plastic Little Tikes toy car as a kid?  Your very own children may have had one.  Now there's an adult version, and boy does it turn heads in traffic.

YouTube, AdamC3046

Brothers Geoff and John Bitmead had the idea to turn a Cozy Coupe into a functioning adult version.  The brothers were checking out a Daewoo Matiz one day and thought it looked a lot like a Little Tikes Cozy Coupe.  So they took a Matiz and completely transformed it.  It took 1,000 hours and cost almost $5000 to build a street safe version of the toy car.  By the way, a Little Tikes Cozy Coupe toy car will set you back about fifty bucks.