@timsley
Nice work to track that down. There may also be other little hidden 'landmines' seeing that device is meant specifically for rental cars. If it's also running a custom firmware and you find there's insurmountable restrictions you may be able to flash original Garmin fw for Drive/DriveSmart 51 to fully convert it. We've done that in this forum with older hire-car devices historically.

Keep up the good work, the initial post above and your earlier one a couple of months back (about the TA10) are the best posts in this forum from a new member for quite a while!