I think it's just you buddy... I also have a 335 07 and ive only had one problem with it... the transmission leaking which i did myself... Other than that it now has 50000 miles and never have replaced anything on it.... no hpfp, no oil leaking, no turbo rattle. I only do the maintenance on it...
Some people just end up with 335 that are a time bomb waiting to happen but i would say thats less than 3% of all 335 out there... I would try to get the dealership to buy it back.