Yellow Car -TDF

And as of a few years ago, the bikes they would carry were CAAD10's.  With a decent set of wheels on them (being that it's a Mavic sponsored car, you'd figure Mavic would provide good wheels), they can get pretty darn close to the UCI minimum weight limit so I think it was a cost effective way for them to carry spare bikes.  Rather than carry a bunch of $10k bikes that need weight added to them in order to make the minimum weight.

(Mavic Neutral Support.jpg)

The bike pictured above is probably a CAAD9.  Not sure how old this photo is, but you can tell it's not a CAAD10 due to the hour glass shaped seat stays.  I do believe they moved tot he CAAD10 though.