Below are 2 sketch proposals for Buick Division that utilized the Monza Mirage body panels and incorporated Buick-specific graphics. These sketches were done by B.O.R.T. designer's Jack Purcell and Jack Juratovic but they never went beyond the drawing phase.
The following is a direct quote from Jack Purcell in regards to the Buick/Olds design proposals ... "It was called the HS, and IIRC, meant "Hurst Skyhawk". We had done the original Hurst/Olds Indy 500 pace car and later were suppliers of the "T-top" parts that Hurst (later Cars and Concepts, Brighton, MI) produced for Buick, Olds and Pontiac (F car) on a drop-ship program such as ours with the Mirage. That was the Hurst name connection with our Buick and Olds H-body proposals and was favorable with Buick and Olds marketing."
Oldsmobile was also offered sketch proposals for a Mirage-themed Starfire but with Olds-graphics and a unique rear facia treatment, unfortunately no photos of those sketches are available.
It is possible the Road Hawk was partially inspired by drawings like this. These pictures were shared by Brian J. who received them from B.O.R.T. co-designer Jack Purcell.