Good Luck with the setup, a couple of things to think about
:
1: Try to figure a place other than the trunk to mount the antenna (maybe next to your temperature sensor in the front bumper)
2: What are your plans for audio. with the Dell Axim the sound level at max is not that great (and if top is down forget it) and the screen is to small to read while driving.
I tried a similar setup in a hardtop SUV, worked "ok" but not great.
Let us know how it turns out, I may revisit it myself.
