I haven't experienced velcro ruining the finish of the keyboard. You can get Goo Off, and I think that this will take off the sticky residue.

I would worry about destroying the keyboard by leaving it in the car - not melting the velcro. I would not leave the keyboard in the passenger compartment where there is the sun and the greenhouse effect. In the trunk, you shouldn't have problems with the keyboard or with the velcro melting.

What do you want to velcro to the keyboard, a picture of your fiance or your electric toothbrush holder?

Beakybird