For those who have an aftermarket GPS unit, where is the best location for a GPS antenna. The unit being used is the Eclipse AVN726e into an 02 LS430 (non-nav model). I'm going to install the unit but I don't want to place the GPS and Sirius antenna outside the car. Where is a good location for these antenna?
Some suggest placing on top of head unit itself and some have mentioned under the rear deck panel. What works best?

 

On my '01 ES, there is a steel support beam underneath the dash but right above the location of the headunit. It's a tight little space but I stuck the antenna on there and it's always had high accuracy.

 

If there is metal above the antenna, will it affect the reception? I was thinking of putting it under/inside the dash behind the unit also, but wasn't sure. I just want to do it right the first time. All the instructions say is to mount where it faces the sky without any obstruction. I don't want it visible due to theft issues.

GoodRevs, thanks for your feedback.

 

YES! Any metal above the antennae will affect reception. A GPS antennae must have a clear "sight" to the sky. Place it in the far right corner of the dash butting up against the window. Ideally, the best location is on the roof/front windshield line dead center.

 

If you do not want the antennae seen and bury it under the dash you will to accept the fact that reception may be less than what is desired.

 

Thanks mkorsu.

I was considering mounting the antenna in the rear, on the rear deck behind the subwooder grille (this was my only option if it HAD to be visible). Will the subwoofer affect the signal? Or will the stock AM/FM antenna in the rear also affect the signal? What do you think of this placement as opposed to placement in the front? Also, if it is the rear or the front, does it have to be dead center?

From what I researched, the OEM GPS antenna on select Lexus vehicles are mounted under the dash and away from plain sight. Why do the aftermarket antenna differ when the OEM antenna gets great signal being buried under the dash?

 

Just put the GPS antenna under the dash. Most of them come with a metallic pad so you can put under them. Under the rear deck is another good choice but may not reach all the way back there.

 

Placement on the rear deck is a very viable location. The subwoofer will not interferre at all.neither will the stock antennae.
GPS antennaes will still recieve a signal if they are under something that is not metal. Metal will block the signal completely.

OEM antennaes work because the manufacturers are willing to sacrifice reception in exchange for a high WAF. (Wife acceptance factor)LOL.