How much of an F1 car is the original car at the end of a season?

by sikhlion Sun 23 Mar 2014, 10:47 am

I've always wondered how much of an F1 car at the end of a season are the original parts that were on the car at the start of a season? Is the car completely changed by the end of a season due to wear and tear and upgraded or are there bits that stay throughout the whole season unless there's a crash eg chassis suspension etc. Also after a crash do they rebuild the car or if it's so badly damaged do they scar it and rebuild from scratch?