There are millions of cars on the road in NYC and hiding 200 vial of test shouldn't be that big of a deal. A routine traffic stop wouldn't yield a car search. Also if you are transporting why not drive carefully or take the subway? so this would lead us to believe that there was a tip off.
with that said this may mean bad news for the Yankees, now we have to search around for a new supplier otherwise we might not make the playoffs again.