I happened to run across this thread again and figured I’d provide an update to my comment above.
We were on an extended trip and I wanted to run the wire for my dash cam through the dash instead of up and over it. When I opened up the dash, I found the GPS antenna coiled up under the dash immediately behind the head unit. No wonder I kept having GPS reception problems.
After unrolling the cable enough so it would sit on the dash next to the windshield, I (mostly unsurprisingly) suddenly got *amazing* GPS reception. The info screen was occasionally maxed out with GPS satellites.
I’m going to do something more permanent at some point, but this should give you an idea what I’m talking about.
And you get to see evidence of the bug splat collection we obtained during that particular leg of our trip.