Kilometers to miles. I forgot how I did it but I did, point being is it can be done just keep fidgeting. As far as installing it. I did my own install. My car is a 2004 and they did not come with nav. All I did was slide out the old, unplug it and plug in the new. plug in the GPS antenna and slide the radio back in. Takes about 5 minutes. Then open the side panel on the passenger dash and put the GPS antenna on the ledge on the top of the dash and you are done. I could do this to anyone's Crossfire in 10 minutes tops. Not sure what was back wards or how they could possibly screw it up.