One thing I have already done to the holder that comes with the HP-1 is applying a Velcro strip to the back of the HP and the holder. If you bump it, it will not fall out of the holder. Presently I have a sandbag that the HP sets on placed in the passenger seat. Works ok as without a passenger. Small car and I haven't figured out a good place or way to mount it yet. My truck is not a problem when I drive it.
Its kind of crazy... buying a new scanner then finding out I might need a older GPS to utilize the GPS function on the scanner.
I do hope Uniden figures this issue out before many more of the HP-1 units are sold.
I purchased mine specifically for "over the road" and long distance trips along with its compability with a GPS unit. Just sold my BCD 996T dues to its inability to do as I wanted without a lot of programing.