Not say scaring him or what, but it's really quite
serious.
First, your car must be "more fierce" than theirs, else stuck
forever in traffic. Then lock the car doors even in car. If anyone
gets down to exchange $ or anything, dun park at those ulu car
parks, best stop by main road and conciously lock car even if short
while. Then also dun drive new car in lor. Later tio
scratch/ravaged/stolen then
You want the excitement of driving beyond SG is okie,
but dun risk your new car, really not worth it. The TP of M'sia
will also esp. aim your car.
Lastly, this is what my family does: place a baseball bat within
easy reach if you want bring new car in, like the rear seats, NOT
the boot. 
Hope this helps 