Installation :
1) put the killer.txd in models/txd (not all mod go to gta3.img)
2) put the killer_vehicle.cs to CLEO

or

1) extract all files from open this! to your gta sa folder

How to use : 
Enable / disable mod writes: "GUNS" 
Enable / disable lock-on [L] 
Change target [X] 
Use the cannon [Backspace] (the button "delete" above "enter") or [I] 
Shoot missiles [secondary fire] or [Z] 
Use the minigun [primary fire] or [K] 
Use the flamethrower [G] 

Compatible with CLEO 4.3 and higher
not included CLEO source code
compatible for All cars (modified or not)
don't install if you have modified rockets
still bugging sometimes on lock-on mode (miss texture (white))