Randy...have a read of the SCCA's stock class rules for shock absorbers.
SCCA Stock Class Shock Absorber Rules...
There are HUGE holes in it. Folks run high end shocks that don't meet the rules for where the spring is located along the length of a coilover (doesn't affect anything at all, ride height or whatever). Apparently it's never been protested though - over a 25 year period. I'm informed that it would take about a year plus to get the wording corrected, clarified, or changed. So 2006 or 2007 season!?!? They want the spring perches to be located the same distance from the end mounts as stock but provide no tolerance for this...maybe that is how they handle the vagueness? If a shock such as the Ohlins comes with a damping adjuster installed so as to require moving the perch away from that end, you then move the other perch closer to it's end to achieve the same preload, ride height and so forth without affecting spring rate, alignment, clearance or anything else.
You could find or make a shock to fit the SCCA wording to be legal. This would render a car "legal" but provide no other outcome other than that for the time, money, hassle and potentially less convenient adjustability. I think it's yet another weanie protest issue for nonlocal autocrossers. Keep that in mind for the Penske project.
Oh yeah...you CAN legally run shocks whose length varies from stock within a 2 inch range. Since the spring perches are located relative to the ends whose overall eye-to-eye length is okay to change over a wide range, you can legally change spring preload and wheel travel!! That might help / hurt some cars. And it could lead to safety issues related to bind on some cars since the suspension can travel further. Same thing in terms of the wheels/tire/suspension hitting things since they can move further than stock. But that is legal?!
On the mirror thing. A smaller mirror or no rear view mirror is not legal. For many people that would change their view of the sky. You don't use the RVM when autocrossing. SCCA allows LARGER than stock mirrors for road racing. I'm told that using a small mirror would provide a performance advantage since SOME drivers may then enjoy a greater view of the course. Like Lee Piccone? It IS legal to twist the position of the stock mirror so that it presents less blocking of the view through the windshield. That way it would block as much view as the smaller mirror, which cannot be used because it would open up the view as much as twisting the stock mirror! I left my stock mirror mount in place so that the large stock mirror could be reinstalled. Neither mirror blocks or changes my view of the course at all.
I agree with Fred's points about staying local in a sense. More common sense and logic prevail at times.