Recently, I did a commonly suggested mod to my suspension. I cut the rear suspension bumper stops on my VX. I hated the way it performed/felt over pronounced bumps in the road. It was particularly bad in two or three places traveled in my commute to/from work.
The worst was a particular hwy lane where the speed limit is 70mph and it's on a curve. With a bump/hump combo, the VX literally wanted to hop sideways a bit. Tracking in it's lane was a bit unnerving. Considering that my stiff-suspension C4 (Corvette) is meant to be as stiff, I had a basis for comparison.
And, the Corvette handled this path with considerably more grace.
So, I cut the bumbers...which had minimal clearance above the rear axle. There was only about 1/4"-1/2" between the bumper and it's corresponding axle-plate. Obviously, suspension didn't have to travel far, before that bumper hit.
Now that half is removed (that bottom loop), the change is significant. The low-speed bumps are as good as any other vehicle. And, that hwy turn now tracks correctly.
I seriously believe the VX was bottoming, and being "launched" thru the bumper-stop. IOW, that dip/hump was throwing the frame up into the air...thru direct connection via the stop. With 1/2 of it removed, the rear shocks have more travel -- and can do their job. The result is a suspension that works as desired.
Now, I can't speak to my config -- as compared to the OEM position. IOW, I don't know how much higher it sat when new. OTOH, the rear shocks don't seem lifeless and bouncy. I've also considered the 1" spacer lift -- but don't necessarily need it anymore -- despite having purchased the urethane "donuts". I'll still probably try them when it get's warmer...but I may have some travel limitation with my PS dual exhaust pipe routed between the differential and trailing link. (As it sits, I have zero contact.)
I still need to post pics/vid of how my dual exhaust turned out, but I'm waiting for a nice day to wash it up and have it look nice.
In the mean time, I think anyone observing this type of body control issue -- especially in the hwy should consider this mod. I actually believe it could make your VX safer. Of course, a lift, new shocks, or both might accomplish the same thing. This option just costs less. And, is good for people w/o leaky rear shock absorbers.