Q: What are the most frequent problems on 2013 135i bmws

Based on data from "Consumer Reports" (i.e., their annual automobile reliability ratings), overall the BMW "1" Series, for model year 2013, has the highest reliability rating that CR assigns. The only sub-components on the "1’ Series in 2013 that had somewhat lower (but still better than average) reliability were the transmission (minor components, not major), drive system, electrical system, body integrity and body hardware. But, again, even at that, the ratings for those sub-areas were still above average. All other vehicle components and systems were well above average in reliability for model year 2013. An additional, extremely valuable source of reliability data for your year, make and model is contained in the public access NHTSA database. Simply search under "vehicle complaints" by inputting your year, make and model and you will be able to retrieve very informative first hand accounts of problems that vehicle owners have experienced with the vehicle. It’s a great way of finding out if someone has "had the same unusual or unexpected fault happen to them". Lots of trends in individual model vehicle reliability end up becoming "visible" in databases like the NHTSA one. Please let us know if you have additional concerns or questions.