Where is the thing to put in more transmission fluid on a 2005 Chevy Cobalt?

The transmission fluid dipstick on a 2005 Chevy Cobalt is typically located on the passenger side of the engine bay, near the firewall. However, many automatic transmissions in this era, including some Cobalts, don't have a dipstick. Instead, they have a sealed transmission system, and fluid level is checked and changed by a mechanic using specialized equipment.

Before you start looking for a dipstick, check your owner's manual. It will definitively tell you whether your specific Cobalt has a dipstick and, if so, exactly where it is located. If it doesn't have a dipstick, attempting to add fluid yourself will likely be unsuccessful and could even damage the transmission. You'll need to take it to a mechanic for a transmission fluid check and service.