I have not personally tried the aluminum ones but I'm going by the experience of an independent MB shop owner whose word I trust completely. He will not install them because he needs to stand behind and warranty all of his work and has seen too many fail prematurely. Factory units only.

The electronic hack solution was in my car until I ripped it out recently. It has never worked, at all, since I bought the car and I cannot see how it ever would from the jury-rigged way that it bypasses the factory system while still using some of the key components like the dash control. I guess I understand how it's supposed to work but it did not.

When is a Mercedes-Benz not a Mercedes-Benz anymore? My answer would be once it gets old and cheap enough to fall into the hands of someone who cannot maintain it properly and factory parts are replaced by horrible aftermarket "solutions" that ironically cost more than the correct parts in some cases. The ACC 2 system is not at all complicated from a repair/maintenance POV but the servos wear out and they are expensive. The solution is a good used part if necessary, not some hack that's guaranteed not to work.

My car came with a thick folder full of receipts showing that the poor lady who owned it before me paid some dipschit scumbag MB shop a ridiculous amount of $$ to "fix" her climate control. All she ever needed was a servo unit but they replaced every other component including the push button control on the dash, (these absolutely never go bad unless you take a hammer to them), two different supposed new servos, (the electronic garbage was on the car when I bought it), and on and on because they did not know the first thing about diagnosing the system. I have access to the factory manual on ACC for 116s and it's all laid out in pretty simple terms for technicians. I guess if you don't have the book, you just guess or ask other morons on the phone or online who also do not have the book and should not go near the cars.

That's the end of my rant. Just because I can buy an old Benz with a quarter million miles for peanuts does not mean that I can repair it like it's an '87 Chevy Citation with parts from Autozone. It does not work out well.