To help you crossing the border, don't cross with any food. buy/eat it on the other side.
make sure your van is in running condition(light/tire) and doesn't smell gas.
Don't give them an edge to pick on you.

Custom officer may do marketplace search on large/valuable item, to look if you screw them.

At 1 time, I cross with a NV4500 2WD gas trans. I said I paid 400$, he search on marketplace and find a NV4500 4WD diesel with transfert case attach to it. price was 2500$ I had to educate him.