When it comes to making a movie in 48 hours, how am I suppose to find cast and crew in 48 hours to even start with?
Like I said before: you gather cast and crew before the weekend starts, so you 'only' need to write, shoot and edit.
Make sure you have a few possible location you can use, so you can have a choice where your script happens.
Me and 1 of my friends gathered a team of 20. The last members were added on friday.
We did manage to create a short in 48hrs.