I have the green stuff you get from the store, a rope, water, and the tool that is behind the lady at the counter
First i enter the shack/workshop next to the Station and grab Water Bottle, then i head to the back, climb up and grab the Bent Crowbar on the roof, then climb down and grab the black hose by the red barrels (left side of the wooden ladder).
Then i enter the workshop/shack again and put the Crowbar i found on the roof in the Vise (Vise is at the bottom left inside shack, and you drag the bent crowbar to the vise to use it) to straighten it out, you also have to click E again to pick it up after you've straightened it.
At this stage, i have a Waterbottle, a hose and a functional Crowbar.
Now, head to the back of the house again and use the Crowbar on the planks that are nailed over that door (Protection against Zombies!), then click E to enter the door.
Now you are with the Lady at the counter, grab the Saw (without a blade) that is standing next to the door and have an encounter with the lady at the counter and a golden key will appear on the desk, pick up the key and head to the shop area, drag the golden key on the keyhole (its in the center of the cabinet) to open the glasscabinet and then pick up the Green Canister.
At this stage, i have Waterbottle, Hose, Saw (without blade) and Green Canister.
Drag Waterbottle (in your inventory) to the Green Canister to combine them (Antifreeze!), and give the Green Canister to the girl w cowboyhat who has an overheated engine at the back of the station.
After the encounter with the girl with the cowboyhat, she puts a sawblade on the hood of the car.
Now drag the sawblade to the saw to combine them and voila! Now you have a functional Saw!
Then head to the Workshop next to the Station (the one where you had a vise), and use the Saw on the Lock on the right side!
Head downstairs and pick up the Red Nozzle on the ground downstairs, the encounter with the duo is optional.
Now you have a red nozzle and a hose in your inventory, drag the nozzle on the hose to combine them!
Give the combined item (nozzle+hose) to the girl (drag item to girl) with the bike at the front of the petrolstation since she has problems with filling her motorcycle.
That should complete the Petrolstation and conclude Futtermans visit there!
Hoping Funkerman will show up in the Jungles of the Amazon, A Piratehip , In Space or maybe on the Streets of San Fransisco next!
More puzzles!