I Run Ozi Explorer for off road, and Igo for on road, in my 7 inch indash GPS.  

I have 2 SD cards, one with ozi & and all the maps I need, and one with Igo and its street maps.

to get it to work, I renamed the Oziexplorer.exe file to Igo.exe- this way the GPS is always looking in the same spot for a gps program.



Hacking a Car GPS
I have done a few of these, and buy used MIO brand GPS from ebay. most I have ever paid is $40. 
you can still use it as a in car street to street, still recharge or run via the car cable, and you gain a lot of functions. 
I run Oziexploer as my GPS, as I can easily download waypoints from my laptop or desktop, I can use good topographic maps, I can create waypoints, and make notes about them or easily rename them. With the desktop version I can create maps, for instance by scanning an old map or map from a mining report and telling the program what the co-ords are for at least 3 points are. 

For those of you that do not know, most GPS systems are actually running a version of windows called CE. However, the device is locked so that the only thing that runs is the GPS software itself. This is true for most GPS systems out there, and especially true of the really cheap ones, such as MIO (which can be had for less than $75 new!) 
What do you gain? First off, windows CE is a true operating system for portable devices, so you can actually do a lot with it. After hacking my mio c220, this is what I gained: 
• The ability to view microsoft office documents, such as excel and word 
• The ability to rip movie and video files to the device and watch them just like a portable media player 
• The ability to listen to multiple music formats, such as mp3s and wavs 
• The ability to view pictures or slideshows 
• The ability to play games, dozens of them, from solitare to doom 
• The ability to run other GPS software other than the Mio version 
So, how do you do it? 
Its actually super easy. I do not warranty that this will work, with all hacks you risk "bricking" your device, so don’t come complaining to me if you break yours. 
1. First, you will need a sd card reader (or a usb cable to access your device) 
2. Eject the SD card from your MIO. Pop it in your card reader, and back up all the files to your local computer. 
3. Format the SD card as FAT32. This is the step that most other tutorials forget to tell you. 
4. Move the files back to your freshly formatted card. 
5. Download Mio Pocket 2.0 from here: www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=109690
6. Follow these instructions: Instructions --- Don't worry, all you really are doing is unzipping files and renaming a couple of them, and then move them to your card. If you need good free software for unzipping rar files, click here for 7-zip. 
7. Take the card out of your reader, insert it into your mio device (that is already turned on) and click the yes button when it launches. 
8. After about a minute, you will now have a mobile pc. If you want to go back to the original, simply hard reset (hold power down for about 10 seconds) turn it back on, and do click no when the installer prompt loads. 
With some devices you will need to do a “hard reset” which normally means holding a combination of buttons down while it powers up. A Google search should help you. 

If you need a hand, just email This email address is being protected from spambots. You need JavaScript enabled to view it.