I've been using 88.1 in the UK. It was perfect in a Honda Civic, but not so great in a Mercedes A5. A Toyota was ok and a Jag was average as well. I think it may be to do with the location of the aerial on the car? It's ok at short distances from my DAB radio at home, but even 6/7 feet away, it starts breaking up. Perhaps someone else knows the optimal frequencies to use in different cities/countries.