Yep spot on. I am however at the point where I don't mind screwing things into my dashboard! I guess you could stick it on with strong double sided tape, or just get a cheap second dashboard that you don't mind cutting into for motorsport if yours is in good nic.
End of the day if you are heading in the direction of putting in a roll cage you may as well cut to the chase! Its a good feeling having cars devoted to motorsport - maybe just go rip out your interior to set the wheels in motion, will make these decisions easier