Train Horn Help!!

I want to install a train horn kit on my 02 taco. I will be placing it where the spare tire should go. I need to know the best kit and options of where to put the Air compressor. I do NOT want to spend $300-500 I want to get the best kit for no more than $300 shipped. Please let me know what you think is the best kit and the best all around for the money. I was thinking of cutting a hole under my bench seat in the back and placing the compressor in there but Im not quite sure one would fit. I do not have a toolbox yet.

 

Be prepared for the

 

I looked into it a few months ago too...price, locating the thing and noise changed my mind. Bought a set of horns from en El Dorado instead