Their official site doesn’t list applicant’s interest as one of their evaluation criteria but, i also see it listed as important in their Common Data Set.
http://www.admissions.uci.edu/applicants/freshman_selection.html
Donating millions of dollars for a new library or medical school is usually very effective.
A tour or two, booked in the students name with the same email address they plan to list when they apply.
If you see them at a college fair, visit their booth and be sure they record your email.
It can’t hurt to subscribe to the school’s twitter feed, friend them on Facebook, follow them on instigram, pinterest, and wherever else they post.