Both the 07-08 cars came with hifi, just a sub amp. I would be banned if I told you what I've got invested in this, lol. Hint; it's cheaper than a set of turbos. This include my 60k n54 complete.
The donor car is the 08 535, my car is the 07 525. Everything is bolt in, plug n play. The only modification I need to do is enlarge my transmission for the n54 block, and run a 6hp21 torque converter. The n54 will have pipes,some type in inlets, and a bunch of maintenance done before going in. It's got 60k on it.
The 3.0 rwd cars came with the 6hp19, the xi cars have the hp21. Same transmission internally, must be a model thing. The top bolt are offset a hair compared to the n52 engines. So when guys are swapping n54 6mt, this is the only mod you have to do. I'm trying to move the parts I can't use, like the awd trans and tcase, the 535 rear looks to have the large diff and axles. I don't think the n52 trans will hold more than 450ft lbs., same with the current diff. The car is wire for the xp21, so that may be the way to go. The hp28 could be an option, seem like 6 speeds isn't enough!
Looks like there is a factory Sirius connections. That's a plus, I have to confirm, but my car may already be wired for the antennas. Some other info that behind the glovebox, the oem CD player sits. Don't have one of these either, but I may be able to hook up the iboc there instead. It may be easier just to run it in the rear where it all goes. I need to reneg on my findings about the body harness, as of right now, there is no factory speaker wiring going to the rear doors.