The Fonz didn't have a jalopy! It was Ralph's!

Talk about screwing with kids! All the kids knew the Fonz only rode motorcycles!

http://justacarguy.blogspot.com/2013/10/the-opening-scene-of-happy-days-hot.html

the Fonz was so in love with his motorbike he had his picture taken with it

And even had an imitator

http://justacarguy.blogspot.com/2013/10/the-motorcycles-fonz-had-on-happy-days.html

Toy found on https://www.facebook.com/That70sPage?fref=photo