Hi, You can buy a Steeda fixed upper rear control arm that is the right length and does not need to be adjusted. This is good for moderately lowered cars and is easier than the adjustable control arms. I had problems with my whiteline adjustable upper control arrn install and the adjustment is confusing. Look at BMR for and adjustable rear upper control arm if you need an adjustable unit, and Its tough to get the bolt thru the bushing on the drive shaft. I paid someone after failing all weekend. You may need lower control arm relocation brackets too. My whiteline ones worked out well with the fixed lower control arms which are simpler. Also look at the maxim motorsport bump stops because the stock ones must be cut because they are too tall and the car rides like a tank when you hit bumps. Panhard bar is also good ideaSo I've finally gotten around to lowering my 2011 Stang this weeked. I'm replacing the shocks, struts and springs. The car has around 82,000 miles on it. Should i replace the rear lower control arms also?