The thing about plastics and polymers on engines, it's for weight savings. Ounces turn to pounds and every little bit they can save turns into the 0.00002% (exaggerating here but you get the idea) in fuel economy returns to meet standards. However, manufacturers have had issues with some of these plastic parts not living up well, great example is the 4.6 and 5.4 modular V8 intake manifolds from 1991-2010, they all fail at some point or another and leak coolant everywhere.
If you really want to be cheesed off by modern vehicles, some of them do not come with a spare tire let alone the jack and kit, just a dinky little air compressor that wont do jack diddley squat when you blow out a tire on the side of the highway. Now the one vehicle (vehicles really) that tick me off with the spare tire situation is the Grand Cherokee and Durango. They use this stupid plastic 5 finger thing to hold the spare tire under the vehicle. It's a real bare to pull that stupid thing out in a shop setting, imagine struggling with that on the side of the road, middle of summer or winter with traffic flying by, not giving a crap that your there trying to get your spare out from under your SUV, struggling to take this adapter thing off.
as far as the job goes, that sounds like a sucky situation. I'd get out of there too. $15 an hour at a small engine shop would be pretty awesome man! 
