BMW is more reliable now compared to what it was before. I used to think that I'd never own BMW after warranty, but that paradigm has changed. My current 550i runs very well and I love every minute I drive the car. So quiet, thanks to Remus quad exhaust, and powerful.
Same thought with MBZ. I bought a C300 last year and so far, zero problem. On top of that I have dealer-lifetime car wash at my local MBZ dealer.

 

its called preventative work

if you treat your car well, and change things before they break its a very reliable car

good oil, filters, plugs, belts and sensors are all cheap fixes and generally account for the majority of issues unless you have a vanos engine

 

+1
Bought mine with 30k km, now 78k km (in 2 years) and no major costs except for normal expenses (bulbs, brakepads, ect.) and the regular maintenaces.

 

Had mine for a year and its an absolute joy. Some issues come up - mine had an alternator issue, which was erradicated by the dealer at no cost and some rattles that I also had the dealer take care off. Another common thing is the sunroof noise, also many people seem to have had issues with RFTs and cracked rims... I could NEVER compare this car to a Lexus though - when I drive it, I feel like whatever happens and even if I have to fix it at my own expence, it is still well worth it.

And I'd suggest you get something faster than a 525

 

i think with any car.. even new you may stumble upon an occasional problem.. i had a fan that wasnt working and the car wouldnt drive.. kinda like she saved me from overheating.. and for that i am ever grateful to her shes my baby girl..