Is the 2015 Mazda 6 a good car?
 

How reliable is it?

So far so good !
 

Recently purchased a 2015 touring 2 months ago 30k miles, no problems so far. Great looking exterior and interior for what it is imo. Not a race car by any means lol but very smooth drivetrain. Honestly only thing I dislike is the 'mazda accelerated warm-up'. A little loud when it starts (around 1500rpm) then idles down in about 30 seconds and sounds fine.

2014 was the first year of this generation. I got the 2018... they say it is proven cause of the few issues from the past models. I think you can go the dealership and install Android Auto or Apple Car play if you wanted. (that is what I did). I think it is a great car. Some people complain about the 19" wheels... be careful with pot holes and curb rash.

The 19" wheels makes the car more bumpy but also gives you increase handling. My car came with 17" wheels and I plan on getting 18" wheels in a year or so. I also plan to keep my car at least 10 years.