Reinvigorated

Well, I got myself a Focus, 1.5T 182bhp, Titanium X, and I'm feeling reinvogorated about hitting the road. Other than economy anxiety (<37mpg!) the car is a real step up from what I was driving before. 

I love it. Well. Almost. It's close. I think there are areas I want and can improve on, so I'm now looking to you guys for recommendations on how I can improve my driving experience.

Some thoughts I've already had:

• Sound system. When I was test driving I noticed one had Sony plastered over the speaker grills. I'm guessing this was an uprated sound system. Mine doesn't have it, and the standard sound system is good, but ain't great. I want better. Does anybody know if the Sony system was much different? How hard would it be to get a hold of some better clarity speakers and swap out? Speakers that drectly fit the existing mounts etc. I'm looking for deeper bass (without going down the bass-box route) and better dynamic response 🔊.
• Related - the Head Unit. The SYNC system is slooow. When I click a saved DAB station, it can take 20 seconds before it tunes in. Overall, I find the large touchscreen interface poor to use. Already I ignore it completely while driving, and I use my connected phone for music and navigation. What options are there to us for replacing the head unit without bollocksing up the console area, maybe to improve the amp output etc and dynamic response? I'm guessing this is difficult to do? 🎵
• Performance. It's OK. It's not an RS (clearly) and I don't expect it to be. Bluefin remap £400 - is it worth it for another 13% performance boost? I'd like to get <7s 0-60 if possible 😵.
• Skirts - the ST styling makes a big difference to the presence of the Focus. Mine came with thin profile 18" alloys, oddly, and without the bodykit they look out of place. How hard is it to retrofit the kit? I think I read somewhere that they simply clip onto the existing bodywork, so no removal of any existing parts? 🏎️

Also, looking for any other ideas. Fancy floor mats? Keep seeing adverts for diamond stitch quality mats from China for £80. Mixed reviews.