Tedious but if you really want to do it;
Put 6/7 crates of beer in car
Set save at the Pub around 12am Saturday (Friday night)
Bought about 20-30 coffee's, some beer and cigarettes, put all into car
Spread everything along the rally track evenly starting from the finish line
Coffee is most important put it EVERYWHERE
Killed green car guy along the way (crashed into him)
When your done you should be at the starting area of the rally but it will be too early.
Just wait till 10am and the tent should spawn to start rally (you can alt tab go do something else)
Obviously your car should be rally ready in advance
Started walk straight away after signing name, waited for the countdown, never went of the track at all and never picked up anything. Just drank beer/coffee off the ground using E and kept going.
Smoked 1 cigarette to clear stress at some point.
Achievement popped at finish line (red signs)
**Do all of this in the same session as re-loading will de-spawn the coffee's**
Good luck, i died from fatigue about 10 secs after getting the achievement :)