I also put a 12 volt cig adapter on my Majesty the other day so I could plug in my Garmin 60CX. The GPS shows me that the speedometer is off about 10%. Somebody was knocking GPS by saying that the altimeter is always off. That is true which is why you want a GPS that doesn't use a barometer but uses 4 satellites for altitude. Much more accurate so don't knock GPS speed because of barometer needing to be reset daily. If you get the 60 don't get the "S" as that stands for sensor which means barometer and electronic compass. Electronic compass eats up battery quicker if you're not on 12 volt and is only accuratea when held level, whick isn't practical. They can be turned to 3 satellite and moving status for compass at any angle by holding the "page button a couple seconds till screen shows the message "compass off". I've noticed some of you have the Quest and it can only be used with barometer.