Megasquirt is not a piggy back it is a stand alone ECU. We have installed several systems in customers cars. Not any buicks yet but that wouldn't be a problem. I have been talking to Mac at Fast Track Performance about making adaptor harnesses for them. Megasquirt comes universal and you sometimes have to make some of your own circuts, we had to build the TFI circut on our last one for a Mustang. There are a couple of bugs in the software here and there but overall it does a bunch of stuff. We put it next to the FAST that I run in my car and looked at each software's features and they are pretty close. I wouldn't by any means say that it is as good as fast but for a cheaper alternative it works really well.
