Hey Walter, I can appreciate that you spent your hard-earned dollars on the Lifetime Membership,...so...
I clicked on "Search"> Advanced Search> put in 'antenna' and username 'BA.', and it gave me only 4 threads. The 3rd one was it. In it there is a link for http://www.impalas.net/forums/showth...hlight=antenna
I sent my pics to the guy via email, but I had the very unofficial measurement as:
"basically it's 25" from the rear body-panel line where the quarter-panel would have the corner piece bolted on and it's 3" from the trunk edge. "
Michael9040 later posted his true measurement: "It is 8.25" out from the rear filler panel seam and 3.5" forward from the center of the trunk lid radius."