Where's a good place to mount these in the car? Does it really matter? I am in a g35 coupe. And would like them mounted so they work at their best.

GPS antenna - You can mount it on the outside of the car if you really want to, but it's not necessary. You can pput it up on the front of the dashboard, or even up inside the dashboard, as long as there is no metal directly over top of it. The satellite signal passes through glass and plastic just fine. I have mine up onder the dashboard near the front ans it gets really good signal.

BT mic - Just about anywhere in front of the driver will work fine, as long as it is pointed at or around your head. In the dashboard, on the side pillar, or up on the headliner is fine.

GPS antenna - You can mount it on the outside of the car if you really want to, but it's not necessary. You can pput it up on the front of the dashboard, or even up inside the dashboard, as long as there is no metal directly over top of it. The satellite signal passes through glass and plastic just fine. I have mine up onder the dashboard near the front ans it gets really good signal.

 

BT mic - Just about anywhere in front of the driver will work fine, as long as it is pointed at or around your head. In the dashboard, on the side pillar, or up on the headliner is fine.

For the mic, does it have to be visible for it to work its best? I kinda want both hidden... i dont trust these audio install shops when it comes to locating a good spot to mount things... i want to be able tell them exactly where to mount it

I have my antenna mounted on the dash right up against the wind shield. My mic is mounted right next to the rear view mirror. These locations work great in my car.

this is where / how i mounted the gps antenna.

on the roof next to the radio antenna.

Yes, the mic needs to be visible. It can't have anything blocking the path between you and the microphone.

I pretty sure you can get G35 with bluetooth so i would research where they put mic for factory bluetooth install. that usually hidden that you can't see it normally but would have hole drill so the sound still get through