Well, this trail map is full of surprises.

I installed it in my StreetPilot 2730 as gmapsupp.img. I can see the trails and that map is indeed transparent, so my City Nav is visible underneath.

But it completely screws up the Find function. Trying to find almost anything fails, even places you know it knows about. The screens act oddly, menus pop past you with no delay or warning and only a limited number of choices are available. Very odd. I disabled that map, leaving only City Nav enabled. Same results. I then removed the .img file, rebooted and things returned to normal.

Not recommended.