Gonna have to do that now! At the same time though - WRC vehicles probably aren't quite the sneeze and you break it multi million dollar precision instruments F1 cars are.
Peak WRC is even more advanced than where F1 is now. There's a crazy rumour that during Group B WRC, the Audi rally car was so fast around Catalunya, it would have qualified 7th on the grid in the f1 race. Those cars were absolute monsters and pretty much pioneered 90% of the tech you see in modern day road cars. launch control, rear stearing, turbo and supercharged engines (or twin turbo charging) AWD systems, active suspension etc.
In modern times, no, they're alot more robust, but so are F1 cars. The parts are expensive but they are design to take an absolute battering, they have to be.
Also, the thing about modern race vehicles is that everything comes off or gets put on in sections. Its very rare that individual parts are assembled even at the race track. In any event, there's a good amount of pre assembly to reduce time.