My final step was to adjust the shocks to allow 3 inches of compression with me in the car, and it's made a huge improvement in both ride and handling.

In case anyone stumbles upon this thread, here's the process I used for setting up my rear coil-overs (many thanks to others in this forum):

1. Weigh the rear of the car with the normal load (you and a passenger). In my case, this was 1105 lb.

2. Know the spring length. For me, that's ten inches.

3. Measure the shock angle. I mounted them at 20 degrees.

4. Consult a reliable tech sheet, or contact the manufacturer to get the recommended spring rate factoring in the three variables above.

5. Mount the shocks and adjust them so that with the same load as in Step 1, the shock extension is what the manufacturer recommends. In my case, Carerra (now QA1) recommends 3 inches, or 60% of total shock travel.

By the way, if you don't have access to a vehicle scale, you can do as I did and use a bathroom scale with a 2nd class lever.