First of all, which spacer kit did you get?? A Gregg Dupree spacer kit??
http://www.specialtyz.com/suspension.htm
These only mount on the bottom portion of the subframe bushing....
Or something similar to the attached??
http://www.jspec.com/p2msubspac.html
These mount above AND below the subframe bushing....
If you have the Gregg Dupree spacer kit, then you still need to install the remaining two spacers. The rear subframe has four mounting points. Two are in front of the rear tire by the frame rails. Look for an angle type bracket, (something like this < or this >). Did you check this install link when you installed your spacers?? Take a look at the photo at the top of the page.
http://capitalzoftexas.com/techtips/
Anyhow, hope this helps...
ID