I skimmed through the FAQs and could not come up with an answer.

I want to get the 500bt for my car as an ad on. I have the wiring the unit part down.

After reading all the specs I realize what is involved and think I can integrate this unit

into my car for a dash mounted system with a cover so it looks like it belongs on the dash.

My delema is this. Can the mods i.e. speed cam, the launcher program, backgraound changes and other mods be done to the 500 bt or are they reserved for 700+ ?

.. okay sorry ... I just came across a mazda 3 install here which explained everything... except the mods thing, Can i install ALL the mods that are done on teh 700+ or is there a list of ones only 500 compatible?

Yeah, you can install them all. I haven't come across one that I can't. You have to check your sys.txt and make sure it has the appropriate code for 500BT at the top.

If you have voice control it would be.

[device]
type="PIONEER749UC"

If you do not have voice control it would be.

[device]
type="PIONEER749EW"

UC is for USA and Canada I think... and EW for the rest... I'm pretty sure anyway.

Good luck.