I did one in the mid/late 90's to a 88 Fiero Coupe.
175 (+) HP that got 38 MPG on the highway.
I had planned on cutting off the roof and putting a convertible top on the car and calling it a 1990 prototype (i.e. 1990 Pontiac Fiero Spyder and even had a look-alike factory window sticker with bogus info and prices on it for car shows) but the guy that was building the pieces never came through with the top.
I hadn't cut the roof off, yet so I put the car back together and kept it as a Coupe.
FYI the bell housing for the Q4 is different than the 2.8/2.5 engines that were in the Fiero so the FWD transaxle that came with the Q4 had to be used. I found that I could use an Isuzu 5 speed shifting mechanism (came with the 2.5L 4 cylinder in the Fiero) on the Q4's Isuzu 5 speed and make it work in the Fiero without too much trouble. The Isuzu 5 speed had a FDR of I believe 3.55:1 so that is why it got the great gas mileage.
The car still took off like a bat out of a very hot place once the rpm were kept high.
That car was built in Texas. I moved it up to Kansas when I moved back to Kansas. Sold it to a guy in Minnesota when I got out of the Fiero hobby. Last I heard it was sold to a friend in Colorado.