http://i.imgur.com/BhHxe.jpg
With this CLEO modification the Securicar will drop money when exploded, Source code included in download.
[*]Securicar will drop a amount of money between $1000 and $10000
[*]You will get more 3 wanted level stars if YOU destroy the Securicar with weapons, so try other ways to destroy the vehicle if you don't want trouble