DIY rear coil spring mount reinforcing. Who has done their own?

[jff45]

I have also been looking at this kit, would it work with airbags?
Cheers

My understanding is that the cracking is often caused by fitting airbags in the first place although I'm sure they don't like constant stump jumping either.
I plan to fit airbags for towing so that's why I'm doing this mod.