If you have alloy wheels, they corrode where the tire seals on the rim. Spray some soapy water around the wheel where the tire mounts, front and back, and the valve stem. If you see bubbles you've found the leaks. Had the same problem with the wife's 99 Jeep. Lots of corrosion and one leaking valve stem.
Original tires? Still under warranty with low miles on them (not the dealer, the tire maker)? Could be leaky valve stems. How long does it take for ALL of them to go flat? A number of places will check your tires for free. On the west coast, Les Schwab is good for that.
Are they inflated enough? Having low pressure can mean the bead doesn't seal tight and bumping them on curbs can cause you to lose air.
if it is all four then you may have an old set of worn tires or you managed to hit all four tires on something causing small leaks in all of them. Some bargain tires will lose a bit of pressure over time. Also the type of tire a low profile tire are more susceptible to damage not only to the tire but also the rim.
Chrome wheels?
If yes, get rid of them.
My opinion is that they have leaks
I have a Chrysler 300 year 200. My tires always seem to get flat. What are your opinions?
