Westbound M-8 at I-75 in Detroit: https://goo.gl/maps/XabuXJi3QbwrCzd77
Westbound I-96 at Grand River Avenue (M-5) and Schaefer Highway in Detroit: https://goo.gl/maps/hrLfdhbyAKyvoQa2A
Northbound M-10 at Southfield Road in Southfield: https://goo.gl/maps/1phwL3d5cU9cFWsH7
^ Those are not ideal locations to place an Exit sign, however, there are Exit signs posted at the beginning of the EXIT ONLY lanes--albeit on overpasses. The ideal location would be where the gore split begins. In two of the three locations, it looks like Michigan DOT wanted to use an existing overpass than erect an overhead gantry--perhaps to save money?
In all three locations a motorist is already on the exit ramp when encountering the Exit sign! It would be like placing a DIP sign after you went through it. BOOM! DIP (sign).