I was informed, my TomTom won't work on this due to its built-in antenna, and I can't switch it out either to utilize the BT function that the Qstarz supports as an alternative source. While my Nuvi, which is w/o BT, cannot work either when I close the antenna flap and the optional usb port is the mini type.

The usb cable that comes with the 12v charger, is with one that has a mini usb on one end and the other is the standard usb.  

So thats no good either. He recommends to have the unit plugged to car power source when traveling so one will have full supply from charged battery outside the car when needed. Hence, if anyone has some and detailed information, please share with us, thanks.

If my Nuvi has a BT, it would serve awesomely well for reception is being enhanced through this alternative. Hmmm, I may need BT then on the next unit for such purposes. 

Hi. You cannot use any of our Bluetooth GPS receiver on either of your Personal Navigation Devices (TomTom 910 and Garmin Nuvi) because they both do NOT Support Bluetooth with Serial Port Profile (SPP protocol).

I recommend you purchase antenna booster antenna for both units to improve the GPS receiption.

Thanks for that confirmation and header esp.

Can you recommend which or what type precisely does a Booster antenna comes as? With a cable or it needs to be plugged up or works independantly with battery cells in it? 

Does buyGPSnow stock any and if yes, provide link so I can look at its physical shape to make out what you are referring to.

Otherwise, a link to where one is obtainable on line....

 Pls contact Garmin and TomTom directly to purchase the manufacturer's approved external booster antenna. We do not carry them here. Sorry.