is it ok to use a normal gps meant for a car on our bike's? I know obviously if it gets soaked in a down pour it will be toast, but will vibrations from the bike and such harm it in the long run. Reason i'm asking is i have a garmin nuvi 780 that i have been using on the busa for quite a while. I've noticed lately the power button doesn't want to function properly sometimes, and won't turn it on or off randomly. Just wondering if all the vibes from the bike are finally affecting it? Would really like to get one of the motorcycle garmins, such as the 550 or 660, but they're so dang expensive!! Plus the 780 is a very nice unit, also have the garmin nuvi 1490T i use in my truck, so the 780 is strictly for the bike