Hello, brand new to this forum so apologies if people are sick of this topic but; I'm looking to improve the audio in a 2014 Octavia SE liftback that I've recently purchased. From what I can tell I have a Bolero MIB1 head unit with the standard speaker & amplifier setup. Coming from a 2012 Volvo S60 (that turned not to be road worthy from the dealer 🤬) with a pair of good 6.5" subs in the rear doors, not having a sub at all (afaik) makes listening to music in the car just a bit sad. I'm not looking to shake the rear mirror, I'd just like to enjoy my music again. I've read a few posts here on this topic but I want to get input from people who have done this. (I've been working in PA/VA for a year so I've started getting to grips with general audio & electronics but I've never done anything with music or car audio.) I'm currently thinking of adding a pair of subs in the boot cubbies, I assume I'm going to need a new amplifier (either additional or replacing the stock one) so input on recommended subwoofers and amplifiers would be great, as well as their install. I saw @1loud1 's post on upgrading his canton sound system so my current plan is to use the sub enclosures linked in his guide. After looking into it further I am unsure whether I can actually do any of this with the Bolero head unit currently in the car. I'd like to avoid spending a huge amount on this as I don't know if I'll end up owning the car for more than a couple of years, so that limits how much I'm willing to do. I suppose my main questions are: -Would adding a sub(s) require replacement of the head unit or can I just replace the stock amp with one with more outputs? -If so, is it worth it? How much would that cost, can I do it myself etc. -What amplifier & subs do people recommend for this? -What are the best resources for guiding me through the install process? Let me know if I've missed out any important info. Thanks in advance!