used avic n3 in a 2006 impala

I obtained a used AVIC-N3 off eBay; it came without the initial DVD's.  I bought the CNDV-70MTP DVD's but I can't get the unit to read them.  I have the unit installed but I get the standard "please insert disc" message when trying to access Navigation.  I did a search on AVIC-N3 but didn't find a relevant question so hopefully this isn't a duplicate.

I would appreciate insight on the following questions:

Does the N3 have a hard drive?

Do I have to push the reset switch at any point?  (The radio and AUX features seem to work okay).Can I use the latest upgrade DVD's on the N3, or do I need to obtain a copy of the original DVDs off eBay or elsewhere?I installed the unit in my 2006 Impala w/o a GMOS-LAN-01 module.  I've never dealt with the ECM module, (I saw in another post that the ECM is located in the engine well behind the drive side door in the air filter cavity), so was not 100% sure where to connect the Speed Detection Sensor wire.  I read in another forum that if I install using the GMOS-LAN-01, I don't have to splice the speed detection sensor wire nor the parking brake lead or any of the other wires.  Question:  Is this true on a vehicle that didn't come with OnStar from the factory?  If so, do I need to find the factory receptacles provided for an OnStar installation or is there something in the GMOS-LAN-01 module that provides this bypass?

Sorry for all the questions and thanks in advance!

No hard drive The reset button should not have to be pressed. Speed sense will not keep the GPS from working. Lack of DVD will.   Will it play a DVD or does it just have trouble with the Nav Disk? Those are the only 3 I can answer.

i am an idiot wrote: No hard drive The reset button should not have to be pressed. Speed sense will not keep the GPS from working. Lack of DVD will.   Will it play a DVD or does it just have trouble with the Nav Disk? Those are the only 3 I can answer.

Just tested and DVD movies play fine.  I put the CNDV-70MTP East DVD in and pushed the NAVI Menu button and was told it was the wrong disc, so that may answer my original question regarding whether or not I need the initial DVD, (just need to find the version).

Thanks for your feedback!