Fictionalized Account of Auto Industry in 1960s-1970s?

[beachboy]

This forum has been a great help in clarifying fading memories about my early years in Michigan, and I am grateful to all the DY correspondents for your tolerance of my eccentric questions and posts...

Now I am writing to ask for help with a senior moment: Approx. 40 years ago a novel about Detroit and the auto industry inspired me to try to work in engineering. The book is no longer in my bookcase, and several of my expat-Michigander friends attempted to help me recall its author and title. No luck thus far, and Google has been no help...

Here are a few clues that those of us who read the novel recall:

-- Part of the plot might have been modeled on the then-"golden couple" John and Kelly DeLorean - and their marital troubles - the protagonist somewhat resembled JDL, and he certainly had problems with his marriage - workaholic lifestyle, etc.

-- A central plot of the book [[IWRC there were several) was the design and initial steps to manufacture of a car we think was called the "Orion"...

-- The Orion car [[if that's what it was called) had a problem with vibration above a certain speed, and there was a sub-plot about this near the end of the book that involved some driving on a test track. IWRC, the problem was eventually fixed by attaching a metal plate to the body or chassis...

-- The protagonist [[can't recall his fictional name) had a "hobby", where he would sit in his office and estimate the traffic density on the freeway [[Lodge?)...

-- Either the auto development center or the residence of one of the main characters was located in the fictional town of "Ilium" [[pun on Troy?)...

Unfortunately, that's all we can remember. Can anyone possibly help with ID-ing the author or book title?

Thank you for your help, and for tolerating my mental defects ...