In the walking flames section, I tried to use the van to get higher, but I still can't reach "where the grass reach the highest". So if you have any clue, let me know because I have absolutly no idea how to reach that spot.
(spolier) You just have to place the SealBreakerTM on the spot where the grass grows more than in the rest of the level. But first, you have to get the walking flames to the unlit torches (which should be not very complicated).