IE themselves reccomend a 10A minimum battery charger, not a voltage source (though I’m sure a stable voltage source would work as well). I’m just going with what they recommend.

The main power draw when flashing with the IE tune at least is the fans that come on, apparently. I’d have to remove the corresponding fuse. Could do that, or plug in the battery charger

You know nothing of the engine or tune I’m going with, apparently

You are making a ton of assumptions.

First off - my car is supercharged. It’s the 3.0t, not naturally aspirated.

Secondly, where are you getting pricing from?

Thirdly - it’s good for a 140hp increase. The 3.0t supercharged used in many audio has tunes from several different vendors that are capable of 400+ hp. IE, the one I went with, is 415

If your voltage drops too low while flashing your ecu you can fuck it up - same idea as turning your computer off in the middle of writing data. Wherever you’re writing data can become corrupt

True, I’ll look into my lease before attempting. Good thinking

Car doesn’t have a turbo BTW. I also don’t plan on ever bringing it to a dealership, I’ve got a really good mechanic close by