I agree...no real need for gps on SXM.
Phone: for use inside/outside of rental= Sharon (reasonable cost)
Own Phone: for use on wifi (wherever)..Skype (airplane mode enabled) (cost minimal)
Own Phone and data(assuming you have an unlocked phone) sim card (cost depending on data used)
AT&T(like Verizon) has a $40/month plan also but adds $1/minute voice and also a limited data allowance. Probably not appropriate
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