Mine are flat on the bottom and wrap around posts on the top.
I went with stiffer springs that kept stock ride height. When I removed weight from the rear of my car, I had to remove a third of a coil to bring them back down to stock height. I did this at the top, where it wouldn't change how they seat. No issues.
My car is already pretty low, and personally I won't go much lower than stock. I already scrape getting out of my driveway sometimes, and bottom out on the snow in the center of the lanes during winter. More than once I've gotten into situations where I've lifted all 4 wheels off the ground.
A small cut goes a deceptively long way.
