Bose will forever and always be crap.
If you care about audio quality at all, never get it.
The one exception is their portable Bluetooth speaker line. It's quite impressive in the range but also incredibly, ridiculously expensive. It's impressive for how large a space it can fill with music, not for the audio quality though.
I used to have a 2002 Mercury sable. I replace the head unit with a $100 unit from Pioneer along with 4 ($25 each) speakers and it was so much better. I don't need boomy bass so I don't have a subwoofer.
I did a lot of comparison shopping (Ford Focus, Honda Fit, Prius, MINI Countryman) - many times the low-level audio option is better than the high-quality option. The average price for the stereo upgrades was $500-$750. They all sound worse than $200 off-the-shelf components.