In general, this looks very good for your first build. I agree that a clear coat would be a nice addition to the paint, since it looks quite flat (lusterless) in the photos.
One other pointer, if I may: spend some time on body prep before you paint. It's not fun work, for the most part, but it makes a big difference in the look of the finished model. Take your time and be sure to remove mold lines, flash and other body bugaboos with a file, sandpaper and/or an X-Acto knife. Fine steel wool also works well for smoothing out small imperfections. On your build, there are two mold lines on the tops of the rear fenders that are quite noticeable, and some time spent fiddling with the engine hatch would probably result in a better fit. Remember that attention to the "modeling basics" can really make or break a build.
Other than those two little faults, I think the Testarossa looks quite nice. Good work!
-YL