I found a Nav DVD version 9.1 for sale, but I'm concerned about getting it. The price is ok (around $200), but the DVD says U24 on it. The ver 5.1 in my car (06) says U40. I had a problem with a previous DVD purchase not working in the Prius and had to give it to my wife, who drives a Sienna. (It worked in the Sienna) What does the U number actually mean? Is a 9.1 U24 compatible? Thanks!
