As the cars are doing well and I don't like to sit at home and don't do anything I deciced to write a post about fitting an air horn into your car. It had to be cheap loud and does not require a compressor (like the truck has).
I bought on E...y the loudest available horn 150dB. Basically louder than trucks on the road. I was comparing the noise to Scania Man and Renault and I have to say the loudest was mine.
I do not know if that will pass the test but there is always an option;)
Below full instruction for Megane mk2 and few pictures from Grand Scenic.
Right so step by step :
As a set you should get the trumpet, pump, pipe and fittings. Make sure it is for 12V not 24.
Horn will be placed either before your radiator or under the bumper. You will need to remove pins under the bonnet and pins and screw on the wheel arcs.
Then remove the bumper
Locate your original "audible warning"
Measured current on the compressor is 6.5A when connected to the trumpet. So 7.5-10A fuse will secure the circuit
Checking if it will fit
You need to cut the 2 wires going to electric horn. Then use the terminal and connect cut cables and cables for the air horn pump. On 1 of them put the fuse. If you will have a problem on the test you may just remove the fuse from that little black compartment which is on picture below. This will cut off the current from air horn while normal horn will work.
This is drain pipe coming from battery (battery liquid)
Fog lights
Now here is example of fitting horn in my second car - Grand Scenic
PLEASE NOTE: If your horn does not work but you can hear pump making noise, then you will need to connect wires to pump in opposite way. Then test it;)
Thanks!