No worries mate. I've changed the tape once in the last two years and no issues. Not sure what tape it is, but it's white, thin foam - probably 3M something-or-other. I tried clips first but they made the nav stick out too much. The tomtom holder fits perfectly into the GTR round vent - like it was designed for it! I'm sure you could try Velcro if you were worried and there would be a way to "tie" one side around the blades of the vent to avoid anything sticky.
Haven't tried it that way but thought about it!