Please see the most recent updates in the "Where did the .com name go?" thread. Posts number 16 and 17.
Check Avsim and Flightsim there are 2, one by John Woodward and one by K. Ito both FS9 planes but work okay in FSX/SP1 don't know with SP2 or Acc.Anyone know if there are any Aircoupes or Ercoupes that are FSX compatible? Either payware or freeware?
If you look on the in-developement page at Aeroplane Heaven, there is hint that a Ercoupe is being developed.