When you are sweating passing the particulate test
 

Saw this several years ago and was reminded of it by a meme. Took me hours to track down the real thing.

Link to real thing: Drive The Change

Meme attached.

That's a good meme. When it comes to aftermarket particulate filters, I remember around 2004 or 2005 there were some tests in urban transit buses in São Paulo (they were not mandatory in Brazil yet), and the trapped soot instead of being reduced was collected and used on rubber processing, and ultimately the rubber processed with that soot was used for retreading of the tyres fitted to the buses. Since factory-fitted DPF became usual in Brazil, with the regeneration in effect, it's not usual to recover the soot for industrial purposes anymore.