On a dry day I usually leave the windows and all the compartments in the car open
and the back seats folded forward. I have the all the compartments completely empty. When I go for a spin I leave EVERYTHING that won't fit in my backpack at home.
If they do enter the car the jack and the spare wheel is all they'll be getting.
We should have an awareness campaign as these Inbred Sh1t Bags won't stop doing it until people stop leaving stuff in their cars.
I drove into djouce car park one day and there was a line of about 6 cars with there side windows smashed.
Do what we've been doing in the Kite Surf world...... report to 999 Gardai plus local station. Gather info eg: suspicious car regs etc. Be vigilant, don't leave your belongings on view or just leave all at home. Stagger start times for spins so that there is always someone coming and going in car parks.
Alternatively park elsewhere and cycle to trailheads.
Now I must admit the Gardai are limited in both response and resources but at least each incident gets logged.