I had bought a set on ebay saying they were for 2005-2011 Mustangs a few weeks ago, then I checked Eibachs website as they were in the mail to me and Eibach had an update saying they were developing 2011 specific springs. I called Eibach and he said there is very little difference. The 2011 is a little bit heavier in the front, so the 2011 springs will be a tad stiffer in the front to compensate. But, not that big of a difference.
So I went ahead and installed them. Took about 2 hours total for all 4 corners. I love the stance. The front sits about 1/4" lower than the rear.
Then I wanted to get it aligned. Everywhere I looked online said I'll need camber bolts. So I called around to EVERY store in the Rochester area that I could think of (about 15 places) and no one had them, they'd have to order them. My last attempt was Napa, and they had them in stock.
I go get them and start looking for a place to get an alignment. Ended up going to or calling about 10 different places, they all said NO after I told them I had a lowered '11. Last place I tried - Sears. I've had most of my cars in the past aligned there and they always did a good job and since they sell Eibach springs and install them, I figured they could do it. They asked me if it was alright if they used specs for a 2010 because they don't have ones for a 2011 yet and I said sure.
I gave the guy the camber bolts and left to walk around the mall. I get a call not too much later saying that my car is done and that the camber bolts WERENT NEEDED. The only thing they had to adjust was the toe which was way out (.23 degrees toed out, brought each back to .10 toed in), and the camber was "within spec" at -1.3 degrees on each side.
So basically, if you get the Pro Kits and want less camber, use the bolts. But the spec range goes up to -1.5 degrees so I'm trusting that the tires will be OK for a while. Word of advice though - install the camber bolts yourself if you're going to use them, Sears wanted $36 PER SIDE to install them.
And yes I love the ride. I'll get struts next.