Nope, they installed the right set.

Whoever ordered your truck ordered the "nicer" Infinity speakers, just not the high end Infinity head unit.

My truck was the exact same way. I am also 99% sure that if you take off your door panels, you'll see small half moon shaped amps bolted to the sides of each front door speaker. Silly design, but eh, what can ya do. And it works, I guess.

 

Is this the CD/tape Infinity one?

http://cgi.ebay.com/Dodge-Caravan-Ra...ayphotohosting

If so, now I know what I am looking for looks like