Here are a few versions of The Dragster Wave sheet music:
The first and probably the best online is from Jellynote. The software is a very impressive teaching tool, which allows learners to change the pace of pieces and play along with a metronome, as well as listen to the piece being played by the computer:
The second version is in video form on Youtube, played on the software Synthesia, and though it is not in the form of sheet music, the uploader has linked the midi file of the piece, which can be downloaded. Also the musical notes are written on the bars of the tutorial and therefore it may be easier to use for anyone who isn't completely comfortable with reading score:
The third and final piece I have found is a handwritten copy which can be downloaded and played. The reason I include this is that it is a simplified version and may fit in well if you cannot get on with the Jellynote copy or are used to reading written as opposed to typed sheet music:
https://sites.google.com/site/horsebackridingegg/ghinzu---dragster-wave/dragster-wave-sheet
