Oil draining over the hot exhaust? Sounds good guys, let's sign it off and start production!
(files.catbox.moe)
Seriously, couldn't they just extend the tube a bit so it overhangs the exhaust pipe???
All fire needs is heat, oxygen, and fuel. You've got all of that there.
The exhaust gets hot enough to burn off oil when it's idling, so I'm sure it's hot enough to burn cardboard.
I'm not going to risk it, the tinfoil idea sounds like the goer here.