This is certainly a subject that should not be ignored
Things like going for a swim at a popular beach, taking keys wrapping them up in a towel, and leaving the whole unattended on the beach while swimming , and hoping for the best, I think we are all done this at some stage.
Anyway what I have done to combat this I use a keysafe

to keep the keys in and use a car safe for valuables

the car safe is attached by a cable, it does take a little time to actually use when one stops but it's worth it for security.
With the key safe that I attach that to a tie down point

My Mahindra Pik-up came with quite a good loud security alarm system as standard, (many new vehicles still don't come with a alarm system as standard (and they should

for $$$ people are paying for their vehicles)) so in my case a smash and a grab -- will be a noisy affair.
This cost for this setup -- as from Bunnings
$35 for the Car safe
http://www.bunnings.com.au/sandleford-70-x-210-x-150mm-portable-car-safe_p4220307and
$84 for the keysafe
http://www.bunnings.com.au/select-access-portable-m-lock-5414d-ea_p4210617With all of this I guess I could still get touched, but at least I don't make it 'too' easy for the criminals.
