Here are 3 off the top of my head:
1. Check the motor mounts for sure. I can almost guarantee that they are either loose, broken or have the mounting holes (at the engine) beaten into an egg shape. Raymond make a great aftermarket motor mount that is thicker and won't crack.
http://www.jalpa.ch/mounts.html
2. Check the shocks for proper operation. My rear's were shot, almost completely flat. I sent them down to Ground Control in California and had them rebuilt. What a difference! Now, I just need to pull the fronts and have the same thing done with them.
3. Clean the fuse box. Seem lots of folks have problems with corrosion forming on the contacts where the fuses mount. A good scrubbing with a wire brush (after you disconnect the battery of course
takes care of all sorts of electrical issues.