Old thread, I know, but I've been looking at all 3 items from 9LR for my Goblin, bad part $3200 plus shipping/wait times....

They said the diffuser wasn't necessary if I wasn't going to track it, but it make the subframe/rear end look a little better and I'm sure it does something for the airflow underneath the Goblin? Judging by the pics on this post, it looks like I would have to drill holes in the diffuser/subframe and install rivnuts myself? I was hoping for the price it costs, no drilling would be required?