Scca class help

[BMW_TUNER]

Here is what I found about the bar.

A. All Stock, Street Touring, and Street Prepared modifications are
authorized. Except as noted by these rules and the referenced
rules, vehicles must be as originally delivered including all road
going components such as lights, wipers, interior, heater, etc.
B. Competitors may pick and choose between all Stock, Street
Touring, Street Prepared, and Street Modified allowances when
preparing an SM car. Apparent conflicts between inherited rule
sets from 16.1.A shall not prohibit any specific inherited allowance.
Allowances inherited from 16.1.A may not incorporate SMspecific
allowances. Foreign spec parts may not be used to
substitute for parts which are required to remain stock.

and according to Stock Rules you can have a roll bar as listed below.

Roll bars and roll cages may be added (See Appendix C). It is
strongly recommended that roll cages be constructed according
to the GCR, though they must be bolted (not welded) into the
automobile and be contained within the driver/passenger
compartment. Roll bars may be welded in. A roll cage has
more than four attachment points to the body or frame, or has
bracing both fore and aft of the main hoop.

[BMW_TUNER]

A little more info from appendix D

Street Modified, Prepared and Modified category vehicles,
and all open vehicles, must have a roll bar meeting current
Solo® Appendix C standards (exception: open cars may substitute
factory hardtops equipped with bolt-in fasteners). In
addition, Stock, Street Touring®, and Street Prepared vehicles
whose owners wish to install, or are required to have, or
currently have a roll bar must have a diagonal brace on the
roll bar. The brace may be removable but must be the same
size/dimension as the tubing used for the hoop and be attached
at the highest possible point on one vertical leg of the
roll bar and the lowest possible point of the other vertical leg
of the roll bar. Bolt-in roll bars are permitted. It is highly recommended
that all Solo® prepared vehicles have roll cages/
roll bars meeting current GCR requirements. Roll cages are
highly recommended for all vehicles and, if installed, must
conform to current GCR Section 9.4.