With this "modification" done, the Nuvi is permanently enabled. Thus you can use with Nuvi with antenna flap retracted or extended. If you want it back to its original state, just remove the metal foil. Simple
For your knowledge, there is no internal antenna in your Nuvi 650. The flap antenna is the one and only antenna
Re-rad antenna only works to transfer the signal from the external antenna to the one inside the car. The internal antenna signal radiation is sufficiently strong to work within the confines of the car.
If you need a stronger signal for a larger area then the signal needs to be amplified. Simple logic.
on that logic too however, I knew about that amplification part contributing the signals but fell short as a result when thinking there is a "built-in" antenna in the 650!!! 
the next time... 
You get a better signal with a direct connection. 
I'd like to have optional alternatives as such and esp. in areas, once out on the road, subject to terrain and foliage etc... and the absence of wire extension to direct line of visibility while still "under cover" within enclosure... is all the reason for this. 
