I have always had a difficult time with my Wilwood set up on the rear of my car, and finally the inspection station failed the E-brake as it won't hold the N* engine when put in drive. The stupid little mechanical piston is just not up to it. I have been looking around for some time for something else I could use and it finally hit me! My daily car is a 2005 Lincoln LS with rear disc brakes etc so I took a good look during some suspension work. The Rotors are 11.8" diameter which is almost the same as my Wilwoods @ 11.75. More investigation showed that a 2000 - 2002 Lincoln has a linkage that will accept the Fiero's cable, so far so good.
I made some templates from lightweight material I had laying around and took measurements for adapting up these brakes. After looking at the Held brackets I bought some 3/8" X 2" bar and drilled it up. The issue then became the spacing so the caliper runs central on the rotor. I found 1/2" to be right for my application. I used Steel pipe for the spacers and have mocked it up in the axle. I know that VW and Subaru's have the same PCD as our wheel hubs and the Passat has the correct diameter rotors too. I am still in the process of doing this but here are a few pics if anyone is interested.