harbor freight sells a cheap kit of the torx-type sockets for about $12.. worked out great for seat removal. the 3 square socket is just a 12 point socket. be advised, when using a 12 point socket, get a good quality one! craftsman, snap on, mac, blue point, etc. the harder steels used and tighter tolerances are key to completing the job and will help prevent excessive blood loss (also save a lot of miles on the truck running to the parts store or dealership for replacement hardware).

kobalt is ok for household work, not auto mechanic work, the tools are pretty, but the fit is horrible and will round off corners of your bolts and nuts in a high torque application.

Why would an auto maker use such stupid headed bolts?

Is it some kind of proprietary royalty favor to an obscure inventor or what?

Surely they don't think that it will prevent the DIY'ers and generate more dealer business?

JB
Have a look at this link, it gives some insight to the different fasteners
https://en.m.wikipedia.org/wiki/Spline_drive

It actually is a bit interesting

for example, you can use a robertson (square drive) bit in a triple square bolt