When we started, we put a tow hitch on the Lincoln towncar we had, and used it to tow a 5'x8' trailer. That was an amusing look, but we didn't (and still don't) own anything remotely like a tow vehicle.
Since August of 2010, we've been using a minivan. Two 10'x10' canopies, up to 4 WSMs, 3 8' tables, 1 4' table, a couple of smaller side tables, cambro, two coolers, chairs, three supply boxes, floor mats, fan -- it all goes in there.
Downside: packing and unpacking, setting up and tearing down camp. It gets old.
Upside: no great outlay on expense to buy a trailer; no worries about where to store a trailer or tow vehicle (not possible at our house); increased range for longer trips as we're not limited to 55mph as when towing; and a rock-solid average of 22.5 miles to the gallon.
If you're only doing a few shorter trips during the year, those advantages aren't as important; but for the years we did up to 29 contests at an average of 6.5 hours one way, ranging up to 21 hours one way, those added up.