Don’t bother doing this. Your son is legally an adult, and the college will not discuss anything with you without his written consent.
From their website:
Students Control Who Sees Their Information
While you understandably have an interest in your child’s academic, financial or disciplinary records, you need permission to access those records. Your student can grant you that permission in a few different ways. See our Disclosure Policies for more details.
http://registrar.ucr.edu/registrar/privacy-ferpa/family.html