I am installing a JVC KW-NT1510HDT system with backup cam and Sirius XM. I have questions that I can't find existing answers to in the forum. Any help would be greatly appreciated.
I removed the stock radio. I mounted the JVC universal backup camera and I'm running the wires. I've connected the GPS system via the wiring harness and tested the unit. Also installed the brackets and mount kit. So far so good.
My goal is to get it in as stealthy as possible with no new holes.
1. Will the little SiriusXM antenna fit under the existing stock antenna base? I don't want to take the time to drop the headliner and remove the base if someone already knows it won't fit.
2. There's a lead for the speedometer signal. Where can I tap into that?
3. Where's the best place to tap into the reverse/backup light circuit in the dash or console?
4. Where's the best place to tap into the parking brake indicator light circuit?
If I find any of these answers on my own, I'll post the info here and I'll document the process.

to the posters who have done DIY threads and how to posts.
TIA