Well, there's this thing called copyright law. You can't incorporate the Dakar or the Mitsu logo unless you change it substantially.
That said, it's only illegal if you get caught! Besides, I highly doubt Dakar would care so much in N. America where they really have very little audience. Mitsu is sorta the same since they're really hurting for car sales in N. America. If I had to put money on it, Mitsu would be your biggest challenge (if you used their logo).
Not really.
Their logo as registered includes the word "Dakar" in their specific font as part of the logo. If you remove the word "Dakar," you can use the likeness of the "masked face" and you are not violating trademark law for our intents and purposes. This is why you will find THOUSANDS of items/stickers for sale using the likeness of the face, but without the word "Dakar." Rest assured, they are not going to initiate legal action to stop a non-official "club" with no web presence, who doesn't sell anything or make any profit, because they had about 40 stickers printed which might look similar to theirs.

Heck, not even Mitsubishi would do that - which is why
http://www.3si.org/ has used the Mitsu diamond logo for years on their website as part of their own logo. None of the following are licensed by the ASO (the owners of the Dakar rally)...
...anyway, it's just an idea. The likeness of the "Dakar" face is not only the very spirit of overlanding, but also represents a unique accomplishment of Mitsubishi, so I thought it was fitting.
OP...are you pretty adept at PS/Illustrator? Do you hand-draw too?