I have a 2013 508 and have been using it for around 4 years now. First things first, the authorized service center sucks! If you car is not under warranty, I highly suggest servicing outside. Secondly, there are a few items which are being recalled (high pressure pump, timing chain, etc) so pls check if it has already been done by calling up the service center.

I have been servicing my car regularly every 9-10k km's and the ATF and every 40k km and so far I have not had any issues.

Some have been complaining about price or spare parts, but i personally think it's not that bad. The price of servicing the transmission oil is about rm350. Try comparing that to other continental cars like Volkswagen.