Because envision it and you can achieve it provided you aren't envisioning anything too hard and achieving requires very little effort, this is a video of Drew Clymer's modified 2003 Volkswagen Jetta TDI blowing black diesel smoke through a jack o' lantern he placed on the car's now-giant and now-vertical exhaust pipe. Dare to dream, kids -- that's the message here. *watches video, shrugs* Then when your dreams fail I suppose just do whatever.
Keep going for the Instagram video with audio.
Thanks to Marc B, who agrees the soot all over the trunk is just an added bonus.