REALLY loud horn...

My son would like a set of REALLY LOUD horns rather than the animic one that is on the car at the moment.

Anyone have experience with these..the compressor would have to be in the trunk and I can see only using 2 or three of the trumpets..

http://www.ebay.ca/itm/149dB-1-5-GA...Parts_Accessories&hash=item20ec90be23&vxp=mtr

Thanks