Hi - my 2015 Model S 70 seems to drop internet radio often enough so I am wondering if it's just because I am somewhat rural, or because it does not have 4g LTE
I was thinking of buying this upgrade:
grubermotors.com
and it says:
"....All cars as of June 2015 for North America include the new 4G LTE hardware. Some cars a few weeks before June 2015 may also have 4G LTE. ...."
My question is if anyone knows of a clear way I can check for sure whether I already have this hardware.
I was thinking of buying this upgrade:

Model S - 4G LTE Upgrade | Gruber Motors
Tesla Model S 4G LTE Upgrade The older Model S vehicles were only delivered with a radio module for 2G/Edge and 3G internet traffic. The Tesla LTE/4G upgrade allows these vehicles to be upgraded to the faster 4G technology, improving performance in a number of categories listed below. Module &a ...

and it says:
"....All cars as of June 2015 for North America include the new 4G LTE hardware. Some cars a few weeks before June 2015 may also have 4G LTE. ...."
My question is if anyone knows of a clear way I can check for sure whether I already have this hardware.