my van has no problems at all.
no cracks smooth ride, been running them for a while now.
i think you have the car way to low, did you buy minitastic springs? they are the best there is.
take a photo of it side on so we can see. i have about 3 to 3.5 fingers clearance between wheels & arch.
you can not have it below normal ride height with these springs unless running race springs as they have less travel, i have the fast road, I have mine sitting a tad bit higher to get a bit more travel as my van is a bit on the heavy side compared to you.
as i said i have had not one problem at all as far as cracking go's
i cracked of a wheel arch but that was due to having it to low testing them, wheels scrubbing and hitting a huge pot hole trying to avoid a truck.
it is trial and error but i love them & not had a problem at all & would not go back to cones.
taken the harshness out big time!
one thing i'm going to stand by of late with mini parts is you get what you pay for.
listen to the guys advice they know to much
i think you have another problem if it keeps cracking though.
checked all rubbers bump stops etc.
keep that in mind.
