Why won't my Volvo S60 2004 gas tank fill all the way up?

If your 2004 Volvo S60 gas tank won't fill all the way, it could be due to a few potential issues. One common reason is a malfunctioning fuel tank venting system, which can create pressure that prevents the tank from filling completely. Additionally, a clogged fuel filler neck or a faulty fuel gauge could also contribute to this problem. It's best to have a mechanic inspect the vehicle to diagnose and resolve the issue.