if you are going with the portable units tomtom or garmin, i work at circuit city. and i loke them the most. install would be around $30-$40. if you get one from best buy/circuit city/hifi buys i would look at the protection plan cause the one from circuit city gives you a gift card for the amount that you spent on it if it breaks so you can buy a new one. no sending it off for service the day you have a problem is the day you get it fixed. those things can be delicate because of the touch screen and no one wants a $500 paper weight. personally i like the single or double din pioneer nav units myself