Are you saying this before removing battery or already in safe mode?

This is helpful for people removing battery power and don't want to mess with code resetting or lost codes maybe.

http://www.realtechnews.com/posts/2144

They cost like $9-15 but I made one myself with a TV cord laying around the house and taping wires and a 9v battery to it.

 

It's not in Safe mode now, but I'm thinking ahead to when the timing belt job is done and the battery is disconnected. I replaced the battery about a month ago. When I did, I connected my 12V jump start box to the cables before removing the original battery so the car never lost 12V.

This 9V battery setup, will it maintain the radio settings through the lighter socket or does the circuit close when the ignition is off ?

 

You can test it by plugging something into it with car off and see if that something works. Yes if circuit isbroken when car is off it won't work. I may be getting this confused with my Jeep that has one all the time but I used it for my Audi battery replacement and it seemed to work.