JBL to OEM NAV Expierience and questions

I just wanted to post how things are going with this changeout so far and also ask a couple of questions. Like what previous posts have stated there are some wiring differences between the two units.

Without changing or adding anything at this point I have a nice touch screen stereo with AM,FM,CD,Bluetooth, and Aux options. Note that the XM receiver is external with the NAV unit and not integrated like the stock JBL stereo so XM is lost, not a big deal.

This weekend I will start doing the following.

1. Splice connector L37 into the microphone which is currently on connector L45. Is L45 even needed for the NAV unit?

2. Install GPS antenna. Probably install it under the speaker grill, anyone have a tip on how to remove that grill.

3. Another GPS question has anyone used the XM antenna for the GPS.

4. Last question is for the L42 connector. Looking for where I may locate the SPD and the REV wire that I may splice into.