I've now had a chance to compare the Audi Sound System with the Bang & Olufsen system in the A3. I've had the B&O in my sportback for approx 3 months, and my friend picked up his Sportback last week with the Audi system. Physical differences: The most obvious difference is the style of the speaker grills. The Audi system has no tell-tale differences to the stock system, other than the presence of the sub in the boot. The sub is identical to the B&O unit, but instead of having B&O branding it says something like 'premium' (can't quite remember). Regardless, it's either an identical assembly, or at a minimum an identical housing. The B&O system adds the silver trim to the woofers on the front and rear doors, and the front units are illuminated with sleek white LED strips. You also get two additional speakers on the C pillars (for the surround sound), and I believe two additional tweeters in the A pillars. Total speakers are 14 for the B&O (705 watts - not a typo!), and 10 for Audi System (180 watts). B&O Speaker layout: Cost difference: The Audi Sound system costs Â£255 above the stock system. The B&O costs Â£500 above the Audi Sound System. So, that's the boring factual stuff out the way... now on to my opinion on how they sound and whether it's worth the extra for the B&O. Note: I've not listened to the stock system, so I can't compare anything to this. How they sound: Both systems were tried with the latest Daft Punk album (RAM), as I think it provides a good range of musical style, low bass, instrumentals and vocals. I used a 320kbps download from Google. Quick tip - if you're looking to try the sound systems out on a demo car it's well worth making sure the fade / balance / focus is set to 'Front', as this really does focus the sound right on the driver. Audi Sound System: Excellent clarity across the range, the bass is well defined and you definitely notice the speech coming from the central dash speaker. The sub kicks in nicely, but only really on the drum beats as opposed to general low bass. The woofers cope brilliantly with the bass, and it's a very well mixed and balanced sound. The volume is adequately loud, and you'd certainly struggle to have a conversation at anything over 75% volume. Aesthetically, you're not going to get any 'wow' factor with this system, it's very discrete. This system compensates for road noise by increasing the volume through GALA, eg: faster you drive, the louder it gets. It's been around for a good few years and works well. B&O system: I'll start with the most obvious difference - THE VOLUME. I simply cannot express how loud this system goes, without any distortion it is quite incredible. I would say the max volume on the Audi Sound System is the equivalent of about 30 out of 49 on the B&O system. You won't want to crank this system above 30 unless you're absolutely sure your passengers share your taste in music. I did find that for the first few weeks the sound wasn't that enveloping, but I now feel that the speakers have 'loosened up' quite a bit, and the sound-stage they produce is the best I have heard in a car. For this system I have also adjusted the bass and sub-woofer up by 1 notch on each, but again - the sub is really only punchy for drum beats or very low tones. You'll be getting the 'wow' factor with this system as soon as it starts to get dark, the speakers illuminate as dusk approaches. The silver trim around the speakers helps draw your eye to them even when they're not illuminated. The B&O claims to adjust for road noise through the use of an 'active microphone' to monitor background noise. At first I thought this might try some clever noise-cancellation trickery, but instead I think it just monitors overall background volume and cranks the volume up to compensate. You'll notice this kicking in when the engine stop / starts. It works well enough but i'm not sure it's a massive advantage of the GALA system. An additional side benefit of the B&O is the ability to play movies in surround sound when combined with the Tech Pack - this is a nice gimmick, but in my opinion is unlikely to be used. Other points to consider In comparison to the stock system both these alternatives give you a centre speaker and a sub. The door design seems to be such that it is very easy to catch / scuff shoes against the woofers when entering and exiting the car. I have had to remove a lot of scuff marks already, and I'm quite nervous about the grills getting damaged / dented on the B&O. Conclusions: If you enjoy listening to music at a reasonable volume then I think you're going to want to consider one of these systems over the stock system (if it's similar to the 8P stock system). I believe the biggest advantage they provide is the additional centre speaker, as well as the increased power output. In my opinion the Audi Sound System is the biggest value for money option on the list. At Â£250 it is excellent value for money, and you'll be very pleased with the quality. Is the B&O system worth an additional Â£500? If you're the type of person to spend ~Â£500+ on your home cinema, hi-fi or audio equipment then you'll seriously want to consider the B&O. Also, if you like your music to be LOUD and crystal clear, or just want that 'Wow' factor when friends step in the car then you'll also want this system. If you generally listen to your music at a comfortable level, or frequently travel with family / friends then I'd say stick with the Audi Sound System - it will still impress when cranked up, and you'll be pleased you saved the Â£500. Of course, there is an argument that fitting an entirely different 3rd party system would produce even better sound for Â£750. But as these cars are still very new I think it's unlikely anyone would want to void their warranty for the time being. That's all folks, i'm interested to see what other people make of the differences and how they feel about the systems they chose. I'm more than happy with the B&O in mine, and it'd be the first option on the list for me next time round (unless kids come along... but then I won't be in a position to order a new car anyway ).