My Mooney was a 1982 M20 J - N666RG  with a Lycoming IO360AIA.
This aircraft was set up by the factory to demonstrate how much avionics could be installed in the instrument panel and was flown by company pilots for the first 200 hrs. as a demonstrator.  It is still owned by a friend of mine in California.

It had a ram air and reacted exactly as I described earlier in freezing rain.

Hank