[Sayyad]

I'd like to thank all of you who post your vehicular modifications on this site. You all inspire me. This post is the beginning of my contribution to this community and the humble beginning of my car's transformation.
I used silver duct tape to update the aerodynamics of my silver Jetta, masking off most of the front grilles (leaving the intercooler air intake open), any possible gaps over the front wheel wells and as much as possible of the rear wheel wells. I also tried to make a front undertray but it sort of took itself apart within a few kilometers.
The tape isn't the greatest for this. I had to roll up the edges of the front skirts a bit (but that's okay; easy to do since the inside edges can be rolled in and stuck to themselves) because they rubbed the tops of the tires a bit. I'm also pretty sure the rear skirts got sucked in a bit towards the tires at speed. And the lower front grille block tore open just a little bit along a tape seam at around 400km into the trip.
Which brings me to what you're probably all wondering: did it work? Yes it did.
The car's previous best was around 4.8ish using dino diesel. With these duct tape mods the car used only around 4.3 litres per 100km using B20. Mostly highway, but all the rest was literally spent stuck in traffic, being tailgated by jerks who were really keen on getting to the next red light.
So I think my next move is to make these mods more durable.