Resources for multivariable calculus:

• Some challenge problems (not multivariable): https://www.math.unl.edu/~mrammaha1/Challenging%20problems/Challenge-Problems.pdf
• Cornell is using workshops activities for their engineering students this year (2017): http://www.math.cornell.edu/~web1920/workshop.html
• Materials from Math 53 at Berkeley (2016): https://math.berkeley.edu/~auroux/53s16/
• Lots of past multivariable exams for Math 215 at Michigan: http://www.math.lsa.umich.edu/courses/215/17exampractice/index.html