Two roll bars look great if you've got a Z3 or Boxster....not so great in Cobra. After 11 years of building, I would rather go with a single on the passenger side than two bars. Given the rough loud ride and wind, my regular "copilot" is my son, NOT my wife. At age 12 he's well below roll bar height anyway. When he grows I guess I'll move the bar to his side, or just let him drive.
-Jon