The trick with the maps is to download them via your home broadband to your memory card....expect a V slow download. Then the system does not use your mobile network data download. You will still have to pay for a "navigation" license.
I have an E61 with the Nokia bluetooth Gps and initially tried the SmartToGo maps but have since swapped to TomTom 6. I have heard that TT6 does not work with the inbuilt GPS of the N95 but a patch is in the works.
If you just want to find your car in the carpark, store your location as you leave, then use the inbuilt nav software to follow the blue arrow to your car when you come back 3-4-5 days later and don't have a clue where you parked
