To be enrolled at the same time in a local college and the HS, so that the college courses count toward HS credits but in terms of rigor equal AP classes.
For foreign language, because college courses go much faster than HS courses, it’d allow him to catch up if the HS doesn’t offer higher level Spanish. Or, alternatively, he could show his interest for Chinese or Japanese by taking either language at college Level 1 and 2 but the languages are extremely difficult so the classes would be very time consuming.
Dual Enrollment works for any academic area your child might want to show prowess or interest in – the best predictor of an A in a college course is… an A in a college course through dual enrollment 
What does his senior year schedule look like?