This is a seat release knob for a 2006 Ford Mustang. It has been confirmed to work also on 2005 and may work on Mustangs of other years of a similar model. It should not require the metal spring from the original. The one shown in the pictures fits perfectly and securely.
I suggest printing it inverted from the attached STL using supports. I used Slic3r to generate the supports.
M2 version works with 2006 and similar model Mustangs.
M3 version was designed by request for a 2014 Mustang and similar models.
I appreciate contributions towards my design work. The replacement part from Ford is $85+ in Canada.
2017-09-04 Update: I have updated the shape to be a little more regular and increased the fillet on the rounded edges. Both the new and old are listed in the files. The new one is labeled as M2. Expect more variations soon.
2018-10-22 Update: It was brought to my attention that the M2 version had a flaw. The mounting hole was not deep enough by 2mm. I have corrected this and updated the file.
2018-10-23 Update: Added a version labeled as M3 which may work on models up to 2014.
2018-10-25 Update: Extended internal shaft of M3 which is confirmed to work on 2014 model by ikeman. Thank you.
The sides of the mount may need to be smoothed down slightly to prevent friction with the bevel on the seat.