I have begun my research on possibly switching over to a 2015 or 2017 A4 Allroad. I know the vehicle had a model change in this time period but I would like to know from current owners what your preferences are between these two models? I am thinking of leaning towards the newer version but the prices on the 2015 models are so much better. Do both have keyless entry? Did CarPlay start in 2017? Are both push button start? Is the newer model roomier or more fuel efficient? Just a couple of variables to compare the two. Thanks in advance for any input you can provide.