I've got a new model Highlander (without moon/sun roof) and drilled the holes and did some remote head installs up front. I'll post pics here when I get a moment.
What I did was pay $15 for 2 days of access to Toyota's
Tech Info System. Look for the Standard tier, 2 day access for $15. Once there, you'll have access to the entire manuals in PDF form for body, engine, electrical etc. For 2 days I didn't sleep and I downloaded everything I could think of for my Highlander that I could possible ever use as a non-mechanic tweaking my vehicle. I focused on removal guides for the entire interior, headliners, NAV/Stereo wiring guide, entire electrical schematics and diagrams, ground points, airbag systems, etc. I reference the downloaded interior panel removal guides often when working inside. Tells you every clip location and type, etc. Also allowed me to route wires away from RFI sources, find ign sense etc.
I can drill an NMO into a new vehicle without hesitation (measured center 5 times haha) but I chickened out on removing the headliner (intensive process with how it's installed), so my two NMO mounts are front and back where I could access the coax from behind the (removed) dash light console, and in the back near the Sirius antenna and accessed by peeling back the tailgate weatherstripping and headliner edge down a hair enough to get an extendible hook in there and snag the coax.
Front coax routes straight to the front dash light console and then follows the windshield seam over to the A pillar. If you run your finger along the edge of the windshield and headliner you'll feel the space I'm talking about. I removed the A pillar cover and routed and secured the coax down behind and out of the way of the airbag. The rear coax goes back to the C pillar (no airbag) and down, then hidden behind body panels until finally revealing under my drivers seat. If I could get the headliner down and B pillar panels off, I'd do a third NMO to keep scanner, commercial, and ham separate but my ham is unfortunately secondary on a part 90 radio. Not sure I could get a 3rd radio up front anyway, stupid modern dashboards.
Airbags are scary unless you understand and respect them. Remove the negative on the battery before working near them. Never work around them blindly, you want to see the whole picture so you don't inadvertently block their path. Visualize the entire deployment path and keep your coax away from that path. The bag wants to inflate in a certain direction, AND any body panels in the way are designed to break away, so don't secure coax to any mechanism that is meant to break away, or would be in front of the bag deployment.
Good luck!