a jku passed me the other day and had stock fenders with some type of rubber extension. it was going the opposite direction but what i was able to see looked not bad. wondering if anyone knows if anyone make a jk specific extension or if they would have been some type of universal kit. having the tires outside the fenders can be a problem depending on who pulls you over.

 

I've seen people use adhesive backed garage door molding to make fender jimmies. Not the prettiest thing ever though.