Possibly the car antenna situated at the back of the vehicle making your signal better the further back you place your device.
Perhaps placing the external car antenna down while trying to connect?

Also some dashboards are laced with steel frame lower down so possibly interfering with those if car audio unit lower down center console.

Also different/more expensive units being better shielded against interference from the devices like the device you are actually trying to connect.
Well thats good that i can actually contribute something as ive been a mechanic for 16 years. Make up for the lack of knowledge of linux lol.
I'll hope to try it out myself when i finally get mine delivered.