So what happens if you spend more than the budget cap in a year?
Imagine your team is at race 19, and both your cars crash out and the only way to get them on the grid next race is to spend more than you are allowed to.
Is there a provision in the rules for this situation, where can I read up on what the Budget Cap rules are?
F1 is about maximising everything, so my guess would be that teams have an "unforseen spending" budget - but it would be as low as possible. So getting into a situation where you have to spend more than your budget might not be unklikely.
Mercedes was already complaining about the Budget at Imola, but it being already early in the season it's possible to limit spending the rest of the season.