Add Sounds to Cars

Sorry if this is the wrong place for this, wasnt sure if i should post in lua scripting or help & support

How do you add sounds to cars?
im doing some minor coding on the cars for a RP community im in, until they find someone better, but i have no clue how to add sirens on our cop cars
so if someone could do a little show and tell for me i’d be very grateful
its for gmod 13

Help me please