you should see if you can get an allen key headed screw or bolt to hold the lights in..

i saw this in a car stereo security mag the u.s one, where a bloke had used allen key headed screws or bolts for holding his speakers in, obviously this will catch any theif off guard because how many theives carry allen keys?

to them its the philips and flat screw drivers!

what you can also do is to use thick ty raps this will also make them harder to remove quick!

you have to use ''IQ'' to beat theives, a few simple measures can make it hard...

i hope this helps...