Chances are you turn the car on and notice a not so awesome new warning light.

 

fyi ...

even basic cell phones give off trackable metadata such as geolocation
and of course who you called/messaged and who called/messaged you.

a burner phone can be associated with you if the right metadata is
cross referenced.

for example, buy a burner phone, keep it turned on in your pocket,
make five purchases with your credit card at diverse locations ...
i've got a good idea of who you are with a high degree of certainty.

 

So my posts and/or bio information say that I own a Jag, and live in western NY. That doesn't really narrow it down too much, and my local Jag dealer, that was for many years attached to a GM dealership, was located about 3-4 miles from my house. So Jags aren't all that rare in my neighborhood. I think that I'm somewhat obscure...

 

The IP address you post from is logged by the forum software and can easily be correlated with the pool of public IPs that are allocated by your ISP. Post from multiple devices - say from your home and from a mobile 3G device - and it's even easier to correlate who you are if you have the means to access the IT address pools of your ISP.

The only way to be off grid is to never use the internet at all or to only use it via TOR or routed via several VPNs.