It sounds like you are running the iFly Aviation application while in the car. So yes, if that's the case, it will continually warn you that you are flying dangerously close to the ground, and to tell you about all registered obstructions in your path as well. We have an iFly "Streets" app (is included with iFly720, or for $50 extra on the 700). Note, if you are wanting to "drive your iFly" around, though, we just recommend that you disable the Alerting, via "Menu => Setup => Alerts and Warnings => Collision Alerts => Disabled". This'll make things more pleasant for you.
Note, v7.5.2, to be released later today *should* fix the sporadic terrain alerts that were occurring for you enroute. Our code was mishandling corrupted GPS messages (which will always happen periodically) -- instead of just ignoring these corrupted messages, we were setting your MSL to 0, which makes the Alerting logic set off the alert sound.
Thanks for the reports. I hope this fixes and clears things up for you.