Bimmernut3 - welcome aboard. I have had few X5's but just recently picked up the X3. You will notice way more traffic in the e53 board and a lot of it is relevant to the X3. As such, some of the questions you post there as well. I'll pass along what the tech at a local dealer stated regarding battery programming when I posed the question to him after a potential new battery install on my '10. He said that it wasn't necessary. Not sure if it applies to the '07 and if a battery swap out would be same as a disconnect, but I would assume so. If that is the case then I wouldn't worry about programming after disconnecting a terminal.

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'14 X1 7000 miles

Hasta luego a

'10 X3 3.0 55k miles
'09 335i 55k miles
'08 528i 94k miles
'09 Mini 88k miles
'06 X5 3.0 112k miles
'04 X5 3.0 128k miles
'99 528i 120k miles