In terms of Gumball and M3W - personally I think it's a good move. It's cheap publicity accross the US, and the demographic for the car is not far off - a strong percentage of enquiries and purchases for the 3W are from the under 30 age group I am reliably informed.
This Supadry branding and Gumball participation may seem unpalletable to us slightly over 30's, but given what I've been told it seems to be based on hard facts and make some marketing sense.
Today's 3 wheeler purchasers will be tomorrows 4 wheeler purchasers so maybe not a crazy move after all.
As for all the stickers on the Gumball cars - this is the price of entry - you are compelled by the entry requirements to place the event sponsor stickers on your car - such is commercial reality..
Finally I'd add - this forum thrives on being a community, and a community that agrees all the time is a community heading nowwhere. I dont' always agree with G, but glad we have all spectrums here - keeps this place interesting and me coming back...