It seems to be a standard fitting on RF's & DRB's. I installed them on mine before I really thought about it (so I wouldn't bother if I was doing it again).
At the end of the day, we all have perspex / Lexan type side windows of some description & they are just so easy to break through.
My philosophy is to leave the car unlocked & to leave nothing of significant value in it. That way, thieves can enter at will (without breaking any windows), discover nothing worth pinching, then bugger off ! (Mind you, I don't remember parking the car anywhere I could not see it 100% of the time) !!
The trick is to have a rock-solid immobiliser fitted (preferably with another hidden kill-switch or two). This will defeat the joy-rider mob, but if the pro's want your car, they'll get it - winched into a metal bodied van (no sat/radio tracking) or at gunpont - either way, its gone in 60 seconds !
I am surprised that anyone would open the doors at a car show (never heard of that happening before, & half the cars at shows have their doors, boots, bonnets open for display purposes anyway), but if that was a concern, then the simple door locks like RF & DRB would stop that (like, who is going to jemmy open a perspex window of a show car just to get a better look inside ?).
Basically, not worth worrying about !
Kind Regards,
Peter D.