Jonathan Martin of the Politico has it on good authority that both Mitt Romney and Sam Brownback are planning to bring 100 buses full of supporters to Ames tomorrow:

Campaign aides for Mitt Romney and Sam Brownback have informed the Iowa GOP that they’ll each be bringing over 100 buses to the Ames Straw Poll Saturday.  An Iowa Republican said that Romney was bringing about 125 onto the campus of Iowa State University and Brownback just over 100.  Tommy Thompson is bringing the third most, about 75.  All told, state party officials are planning on the arrival of 375 buses. 

Beyond Romney, Brownback, and Tommy Thompson, Tom Tancredo and representatives for the “FairTax” coalition are also busing in supporters.  If Mike Huckabee, Ron Paul or Duncan Hunter – the three other candidates contesting the vote – are bringing in motor coaches, they didn’t alert the state party.

It seems unlikely that Huckabee is not bringing a single motor coach in (and I’d venture to guess that Ron Paul will have at least one bus, too).  But if they were bringing in as many buses as Romney and Brownback, they probably would have said something so that special parking arrangements, etc., could be made.