[JimD]

This is the cable that I use and others use for coding:

http://www.one-stop-electronics.com/...&product_id=16

It's $99 and has a serial to digital converter built in. There are lots of comments on coding forums from people wanting to know if a cheaper cable will work. Some probably do. But there are also comments from people who bought a cheaper cable and had to buy another because the first one didn't work.

Registering is a one or two step process depending on whether the replacement battery is the same size and type. If it is, one step. If not, then you also have to tell the car about the battery and that's an additional step in a different piece of software. I haven't done a battery yet but the coding I've done wasn't hard but it can be frustrating when something doesn't work and you don't know why. If nothing goes wrong, it only takes a few minutes. I've seen comments about people coding remotely.