[ArmaniMan]

I have taken mine on long car trips as well and they do fine- we don't stop any more for them then we do for ourselves.

I just use a regular tote bag, but a diaper bag would work too.

I bring:

dishes
food
bottled water
wipes (wiping their feet when they get walked at a rest area is very important- lots of diseases and bacteria can be transferred there, also to clean up any messes)
treats
toys
a yummy canned food (sometimes they will get picky on a trip)
blankets
nutri-cal
their meds
extra harness and leash
a brush

Good Luck!