I have learned a thing. Some people get around the drinking and driving laws by lying about what they are drinking. They will buy a cup of ice for the soda fountain and several cans/bottles of booze. They then put booze in the cup and pretend it's a soda.
That doesn't always work. Cops are usually smarter than that. In my experience, you're better off emptying a rubbing alcohol bottle then refilling it with vodka, because no one wonders why it smells like booze.
You can also hollow out smokes and fill them with pot for a perfectly rolled joint that can hide well in a cigarette pack, though you can usually hide them under the dash in a depression on most cars - many cops know about that, but rarely look there if you aren't doing anything requiring a search. Cartridge style CD players (like on a 98 Pontiac GTP) can also hold about a quarter pound of pot, or quite a bit more of something more malleable, if you're looking to move a large personal amount of something from point A to point B and don't need to worry about retrieving it quickly.
The more you know.