I understand that before I begin any head unit replacement I must first disconnect the negative terminal on my battery. Does that throw the computer settings off or in any way result in something screwy happening?
Thanks.

it will reset your radio when the battery is disconnected...but sounds like that doesnt matter if your replacing it anyways

I just put in a new stereo system and disconnected the Battery... The only problem I had was it reset the VDC system... When I first started the engine the VDC and Slip light stayed on... I found the reset in the manual... Just have to turn key off, take out, put key back in, set steering wheel straight.... then start and drive over 10 miles an hour for 10 minutes.... It worked...

If you have it disconnected long enough then the ECM will reset back to original settings & will have to relearn your driving style. But it must be disconnected for a few hours from what I understand.

you shouldnt have to disconnect the neg battery terminal if your using the correct harnesses and you are careful of the wireing and what they touch ive done hundreds of radio installs and never have i disconnected the battery. I am also a cerified car electronics installer

anytime you mess with any type of electronics you want to remove the power from the battery.... just in case if you touch somthing you wont fry it..... LOL just my 2 cents...

It's a good rule of thumb to do so, yes.

(However, speaking from experience, it's hard to screw-up something doing a simple head-unit swap.)

Better-safe-than-sorry, yadda-yadda.