Do a search in the archives on here and you will find some info. Sounds like years ago they use to be pretty good but lost their good people and went...
I would just think that buyer beware is good enough. Maybe someone wants an off-road only car? People have to be responsible for their own action and...
I would definitely say using the Phaeton W12 Brake ducts is better as they direct more airflow to the brake disc. I think the undertray is important...
I would also say don't go cheap on them, just get the original Bosch sensors. But what I do say is don't buy them from the dealer, you will pay twice...