GPS apps come with SD cards; what about mine?!?

[mlevin77]

I'm trying to test out some GPS apps, but most apparently come with an SD card (I assume, for the maps). But, what do I do with the stuff on my current card? For any of these products, can I keep my card, and simply copy onto it the map for the city that I'm in 99% of the time?

I mainly want spoken driving directions, and am ok with using the network (if that will save space on the card). Google Maps doesn't do that, right? I tried Amaze GPS, and noticed that 1) it sometimes skips to the next step before I physically get there, and 2) even though my phone was streaming announcement beeps to the car's stereo via bluetooth (so, paired correctly), the driving directions weren't coming over the BT. Is there a good GPS app with spoken directions that can let me use my own card?

Mike