Is there any plug and play recommendations? I'm not too clued up on the audio scene but just wanted an improvement on the current speakers but something simple that can just drop in and no messing about
I think the Gladen kit (and maybe that MB Quartz kit) is the closest thing I've found to plug and play. If I'm honest, I haven't done loads of research into it, but Gladen kept coming up in any threads worth reading.
It was all quite straightforward in the mk4, just a case of making sure something physically fitted. The more I read up about the mk5 though, the more it seems a little more involved. Again, I need to read up more!
As @Pudding alluded to, there's probably a better gain in sound quality from amping up the OEM speakers than powering upgraded speakers directly from an OEM HU. And obviously better still amping up some upgraded speakers.
The OEM headunits simply couldn't do any justice to any speakers worth buying without being amped. A lot of decent aftermarket HUs have a much better power output than the oem units, and better EQ control, so it's in some cases possible to achieve decent SQ without an amp. As I did in the mk4 - see my earlier post.
Bottom line, if you want good SQ from an OEM HU, you really need to bring an amp into the equation. If you want decent SQ from an aftermarket HU, you have a bit more scope.