I installed some Koni yellows in my coupe, I have to say those are some stiff shocks/struts very - very nice. And you can adjust them some what.

You may be able to take alot of play out of your ride just by installing a set of these shocks. A set of aftermarket springs would set you back another $250.00 but I suggest if you like your current ride height just install the Koni yellows.

If money is a bit tight, get some heavy duty shocks at the autopart store what ever house brand they have, and get a set of H&R or Eibachs online used or something. New you may be able to find a set for $200 less used.

Else I can't think of anyway to improve the ride other then to replace your stock shocks with the same and go back to a good as new ride.