Welcome.I hope this video and text walkthrough useful
1.press the arrow to view the front of bus.
2.click under the drivers seat and get the gas can ( you may have to press twice to get close up of front.)
3.click on light gray box next to gearshift and figure out the simple riddle.remember its a HOLE!!! you get a bottle
4.click on gear shift, and you should get a rod.
5. go to the back of the bus and click on the second seat to the left, and click on the pack.youll get a beaker.
6. click on the beaker in your inventory, and it should fill with green stuff. ( if it doesnt work facing the back, turn around and make green stuff.)
7. turn and close-up on the square in the middle of the floor. click on it.
8. and your out
Source: Escape Games 24