Will they fit a w124?
124's "Normally" require ET's in the mid 30's to mid 40's, give or take a few. ET11 is too far a stretch, would look like a jacked up 4 wheeler with big wheels sticking outside the body. Most definetly a major fender rub situation. (Numerically low ET numbers move the wheel towards the outside fenders, numerically high ET's move the wheel towards the inside suspension) When outside of a cars design sweet spot for ET, you will be rubbing inside or outside.
These same style 17" wheels were also built with ET28, if you can find a set of ET28's and do some fender modifications, you would be good.
The same seller has a set of same style 16's that are ET35 I beleive, you should jump on those, perfect 124 fitment. If I already didn't have 2 sets of 16's I would have picked them up myself. The 16's look great also, and are really the best setup for ride comfort on a 124, just a thought.
Attached is a picture of Aero I 16's on my wifes E420, in the background is my CE with 18" Mono II's for comparison.
These Aero I wheels don't come up for sale very often, last week a set of 17" ET28's were just sold on eBay for close to $1000, and they were in England, the buyer still had to pay another $500 or so, to get them here most likely. I was very close to pulling the trigger on them, but the shipping killed it for me.
If these 17" wheels were ET 28, this thread wouldn't be this long, they would be in my garage already...lol
Just do a search on the sellers ID for all posts, and you will find the other 16" offering easy enough.
PS: The seller said in his first post that these 17" wheels would fit 124's with spacers, I'm sure he just got mixed up on his thinking. You can't take a numerically low ET and make it higher with a spacer, it's the wrong direction. Adding a 20mm spacer to a ET11 wheel makes it a ET-11 (minus eleven)wheel, not ET31. The only way to do this is major welding and machining. Weld the bolt holes closed then redrill them not as deep. Then machine off the back side mounting surface the amount in mm needed. In order to make a ET 11 wheel into an ET31 wheel, you need to machine off 20 mm from the back side mounting surface. Then the amount of structure left is questionable depending on the wheels design. A 10mm spacer will allow a W140 ET48 wheel to fit a W124 the same as a ET38 wheel does. Spacers numerically substract the ET, and only work in one direction,.