Hey there!
No tapping is required. The risers come with everything needed to install on your car including the proper size screws and threaded wing risers with o-rings for a weather tight seal.
The problem that has been referred to is one or two cases of people having stripped the risers upon installation.
As long as you follow the instructional video, there shouldn't be any problems. The biggest thing to be careful of is the use of power tools. Since these are small pieces, power tools are not recommended and we advise strongly against them for the installation of this part. Hand tools are more than enough. Also be sure that everything is aligned before installation, making sure not to force anything into place.
If you have any questions, let us know!
I think your statement is not entirely correct.
In my case, the tapped portion of the center risers did not extend all the way down to the end of the drilled holes. If I had continued to apply pressure, I would have stripped out my threads, as you are installing a steel fastener into an aluminum thread form, and the steel fastener is stronger than the aluminum. I only used hand tools in my installation. My sugestion is to thread the OEM fasteners into the center risers. If the fastener does not go into the threadform deep enough, you will need to run a tap into the threaded hole. If, upon installation, the fastener goes in smoothly for several turns, but then becomes tighter,
but the wing is still not tight, you will probably need to chase the threads with a thread tap. This is what I had to do to make my setup work. Most likely, there is a manufacturing problem with a small percentage of the center risers. Nothing that cannot be fixed with a metric tap.