How do I know if my windscreen won’t let Sat Nav work?
It is me asked:
Some windscreens have some metal in, I think, apparently. This stops the Sat Nav from picking up the satellites. How do I know if my windscreen is one of those before I buy a Sat Nav?
Satnav-insurance
Some windscreens have some metal in, I think, apparently. This stops the Sat Nav from picking up the satellites. How do I know if my windscreen is one of those before I buy a Sat Nav?
Satnav-insurance

If your car doesn’t have a heated windscreen your satnav will work, some even work with electric windscreens.
Easy check - does your mobile phone work in the car?,
EDIT: have just checked a portable GPS (Colorado) in my car which has one of those sun reflective (athermic) windscreens and it didn’t want to pick up a signal at all unless you held it up by the mirror where there is a clear spot.
it will work with any windscreen as long as it can see the glass it will pick up a signal and work so do not worry about it i have never known one not to work yet
My Ford mondeo mk 3 has heated front and rear screens and my tomtom works fine.Hope this helps