I have a Garmin satnav which is much easier to program than the unit in my A8 and has the benefit of being 3D.  The inexplicable thing is that the Garmin works faultlessly in my Fiat and my VW Transporter but in the A8 constantly loses the satellite signal. As nothing about the A8 is quite like other cars it doesn't surprise me but I am curious as to whether there are some radio or electrical emissions emanating from the A8 that would interfere with Garmin reception. It doesn't matter where it is in the car either, the effect is the same. I have driven the same routes in other vehicles, so I know it is the A8 causing the problem, not the Garmin itself.

 

Garmin, never particularly good in the customer service department claim never to have heard of this phenomena and are insufficiently curious to make any suggestions.

 

Anyone have any ideas?  Mark

Just a thought - I believe some A8 models were specified with Solar Reflective Glass and this could cause trouble with GPS signal. Do you think this could be the case with yours/do you know if you have this fitted?

Based on your comment I just had a look at the windscreen and, apart from the fact that it is micro-pitted in a way I've never seen before (is this the solar-reflective giveaway?) it looks like any other windscreen.  No filaments inside it or unusual components that I can detect. There is no nomenclature visible which would indicate what type it is. My car is the 'limousine' spec, which means that although it loses the potentially useful long load rear seat portal it gains a solar powered sun roof which blows cool air through the car when it's stationary - a gadget that actually works.  Whether this could be interfering with the Garmin satnav I don't know, but it remains a baffling problem.  Mark

Based on your comment I just had a look at the windscreen and, apart from the fact that it is micro-pitted in a way I've never seen before (is this the solar-reflective giveaway?) it looks like any other windscreen.  No filaments inside it or unusual components that I can detect. There is no nomenclature visible which would indicate what type it is. My car is the 'limousine' spec, which means that although it loses the potentially useful long load rear seat portal it gains a solar powered sun roof which blows cool air through the car when it's stationary - a gadget that actually works.  Whether this could be interfering with the Garmin satnav I don't know, but it remains a baffling problem.  Mark

 

Well the solar reflective screen is designed to reduce heat inside the car so the fact that your is limo spec and it has the cooled sunroof I would assume it probably has the windscreen too...

UPDATE to 'Garmin Satnav won't work in my A8'

 

My A8 failed the MOT with a 6" crack in the lower passenger side of the windscreen plus one stone chip in the driver's eye line. Considering it is the original 12 years isn't bad. I had it replaced on insurance (less the £75 excess) and noted that the serial numbers were almost identical to the old one (M982 instead of M981) but without the Audi rings logo. Just out of interest I tried the Garmin Satnav in the car and to my amazement it not only found the satellites in seconds but continued to work perfectly on my journey, with no drop-outs as before the glass change. 

UPDATE to 'Garmin Satnav won't work in my A8'

 

My A8 failed the MOT with a 6" crack in the lower passenger side of the windscreen plus one stone chip in the driver's eye line. Considering it is the original 12 years isn't bad. I had it replaced on insurance (less the £75 excess) and noted that the serial numbers were almost identical to the old one (M982 instead of M981) but without the Audi rings logo. Just out of interest I tried the Garmin Satnav in the car and to my amazement it not only found the satellites in seconds but continued to work perfectly on my journey, with no drop-outs as before the glass change. 

 

Great news!  :D

 

Must have been something to do with the glass then!