I pulled a pair off a mid-70's/80's chevy truck at the salvage yard, mounted them under the "hood latch pan", and they sound like caddy horns. Don't forget to get about 8-10 feet of the wire with them.

1953 Chevy Two-Ton
In the Stovebolt Gallery
More pix on Photobucket

Be careful calling yourself a expert,because an "EX" is a hasbeen and a"SPERT" is a drip under pressure.