no biggy at all... just make sure nothing will fall over(clones mainly), i have a little dome for clones, i tape/tie everything still.
transport tall plants in trashcans with trash bags over/around(construction bags work great!) Tupperware/boxes for small plants... just make sure they are watered the day before, keep the temp right, and stay incognito, and drive well.

don't forget to keep ventilated (hole or two in trash bag) you may want to stop every few hours to let them breath... they wilt heavy under transport, live.

it will be ok, trust me. just stay cool