[shoptb]

I also have a '13 328i, and I've noticed differences in the things that you've described when I'm driving the loaner cars from BMW Service.

The diesel-like sound and feel is an attribute of the 4-cyl engine. BMW has been making refinements to the N20/N26 since its introduction in the F30, and I believe that it's quieter/smoother in the newer models I've driven. I've also noticed that the ASS is smoother in the newer models. (pun definitely intended). I have an F33 428xi on order, so I'll see first-hand pretty soon about the differences. Ask your dealer to flash you to the latest software, and that will make some improvements.

As folks have mentioned, ASD is not included in the '13 model, and it's not something that you can code around as hardware is required. It's interested as to how many folks are wanting to mess with it because it's not "genuine", but the exhaust sound out of the N20/N26 isn't that great anyway, so I'm personally exciting about the new sound, regardless of its authenticity.

I added the BMS Stage 1 tune to my N26, and that has made a perceptible difference in the throttle feel, especially in Sport mode. It's all plug & play, so takes about 10 minutes to install, and the power difference is amazing. I think they rate it at gains of about 40-50 bhp over the stock 240 bhp. Of course, as with any mod, you'll need to feel comfortable with it yourself, especially since you're probably going to be out of warranty at some point in the future.