My experience is similar, I've been holding fire on this for too long.

I was booked in for dump/headers and tune.
Arrived around 9am, coming from Rockingham and told ol tatts that I'd wait locally, as I had no where else to go.
Also told him that there was a flat spot in third and asked for that to be passed along to the tuner.

So I kill myself in malaga for the entire day and get a call around 3pm saying that the car won't be finished today.
No courtesy, nothing just blunt.

So I call my bro to pick me up from joondalup and after dropping him home, I hit the freeway peak-hour in his piece of shit x-trail.

So back up the next day, fuck around getting his car back and get dropped back to the workshop.

Usual story, keys back and pay with no courtesy what so ever from blink182, not even a simple explaination or apology for the massive fuck around.

So drive home and the flat spot is still there.
Get home to check the new parts and there's no fucking undertray.

Call up and 'oh yeah they melt with headers so we didn't put it back on'. Again just arrogance.
No putting it in the boot and telling me.
So I had to wait until until my next trip to Perth then get to Malaga just to pick up my parts.

And BTW I've put some ebay self adhesive silver foil and haven't had a problem.