Consensus is that its a waste of time and money. 
I think it utilises the B&M platform.
Thats a bummer, I'm going to have to research for a decent sat nav. For years I've relied on printouts and using my mobile broadband with google maps and they are getting worse and worse. And I think the 500 deserves something special.
Ha ha ha! It's not just me then. It took me 17 days post-order to weaken and order the Sabelt seats. Not sure about the navigation system. It may be you need to stalk your dealer at least one more time.... It only took a month for my car to be fixed in production though so if you are going to change your mind, make sure you do so soon!
Have you considered the Monza exhaust? That's were I am up to on this whole business. Really, really want one but am beginning to believe those of my friends who keep saying, "I can't beleive you are spending that much money one of those!" but at the same time, I just know it will happen. 
I've ordered the Monza exhaust, four tail pipes you'd have to be a mentalist not to want a car with four tail pipes
I'm getting mixed responses from my friends, one or two think its the best idea in the world, the majority of them don't recognize the difference between an Abarth 500 and a Fiat 500 (they don't drive
) And one or two people at work are taking the p*ss out of me at work saying its a girls car, but I don't care what they think. Having test driven the 500 SS I could find out the real reason its called the 500 is because 500 puppies are killed to produce each car and I would still want to buy one.
