The 2007 Chrysler 300 does
not have a dipstick to check the transmission fluid level. The transmission fluid level is checked by a mechanic using specialized equipment that measures the fluid level while the transmission is operating at a specific temperature. There's no way to accurately check the level yourself.
Trying to check the fluid level yourself could be damaging and inaccurate. If you suspect a problem with your transmission, take your 300 to a qualified mechanic or Chrysler dealership for a proper inspection and fluid check.