Utter, complete bullshit. Even carbide tipped blades still sit on a regular metal linked chain which would be snagged on the torn metal in no time and damaged or destroyed. A rigid blade of some kind, designed for cutting metal, is the only way you are going to use a power tool to can opener a car top.
I’ll concede the possibility. But after about the first 30 seconds, you’re not going to be cutting so much as ripping and bludgeoning