From both sides it is a totally crazy and unorganized place. Long lines, every one is trying to cheat you, especially the cab drivers with their New York prices.
Better to cross from 3am to 6am, if you dont want to get stuck waiting. There is no queue. Throw away any medicines you have because you will have to explain what are they to custom guys.
Dont even think on crossing with you vehicle, you will be stuck for a day or two waiting in the line. More importantly the internal parts of your vehicle might be removed to check for drugs.
Better to fly and avoid this place.