What happens if they mess up?
If they mess up as in scratch the car or break anything, they replace it for new stock item, have this in writing.
In regards to engine going pop or anything well nearly all the kit they are putting on the car does not effect power much if at all. The FMIC might add a little due to cooler denser air.
But they are not remapping which means the cars ECU will keep everything in check and Powerstation shall be monitoring the car and I know and trust Powerstation so happy.