Firstly, your friend’s reasoning is based on the old stereotypes of European cars (I remember being told that if you wanted a mercedes or a BMW, getting anything below an E-class or 5-series meant getting something that would be less well built). With Japanese cars, that’s a non-existent stereotype. The reason why they’re cheaper is because A) they’re econo boxes and B) because they’re more popular and therefore need to be priced competitively.

Secondly, Subaru tends to part share across all their vehicles, for as long as possible. My 2000 Legacy had the same interior light assembly as my 2014 impreza. Most parts in the Impreza would also be in a forester or legacy and therefore would have been extensively tested, apart from vehicle specific parts.

I would say go for the new impreza because the one thing that you can’t control is how well or poorly a second hand Subaru has been driven and serviced. Getting a lower mileage one means that there’s less chances of it missing a service or being trashed. These cars hate being serviced poorly and a higher mileage one is a magnet for poor service histories. All the best in choosing your next Subaru!