I am in the planning stages for my six track car. I plan on running TT with PCA, maybe trackmasters. I don't think I will be doing any wheel to wheel, but do I need that diagonal bar? I will have a full cage. My big concern is how far forward it pushes the passenger seat?

On my car, 4-5 inches. It only slides back a few clicks from the front now, probably not even halfway.

Do your passengers feel cramped?

It's not street legal. They mostly just feel the warm lump in their drawers.

Andy,
I just took one of our main hoop assemblies and positioned it in a customer's car that has the backpad removed right now.
With the passenger seat in its lowest tilt angle, it can be moved 7 clicks back from its furthest forward position to where it hits the rollcage.
Using a tape measure I can see that the forward edge of the seat adjuster handle is 6" ahead of the crossmember when the seat is just touching the rollcage diagonal.

Thanks Chris,
That is very helpful.