Ridetech Coul over instal question

[rcarson25]

I have searched and could not find what I am looking for. I am installing the older version ridetech 4 link setup. In mounting the upper brackets there are 3 self tap bolts you need to to drill for. I cannot for the kid of me figure out how you are supposed to drill the rear two on either side unless I didn’t have the trunk floor in. Does any one have any advise here? Are the rear bolts necessary? The self tapping bolts seem to be super easy to stop from what I have heard so are they even providing real strength/structural load?

Thanks in advance