If you're stuck for Halloween costume ideas and have a group of mates who are up for it, we doubt you could do better than this.
The Nothing To Do Crew's real life Mario Kart race may infringe on some copyright and intellectual properties, but it's all in the name of fun and adoration for the Nintendo game that everyone loves to play/scream at their TV to.
There's a lot of effort involved but the payoff, we think, is worth it. You have a week, so step to it.
Via YouTube