There are many nice speakers around but unfortunately the mk5 Golf has a major issue with the location of the mid-bass drivers. I have tried the most expensive and exotic drivers in my doors (including the Focal Utopia top of the range) and none of them sounds right because the position of the drivers is on the back of the front doors wich makes them collinear with the listener's ears. This is never a good thing since the sound coming from speakers collinear with your ears would always be out of phase. The only way to solve the problem is by rebuilding the door carboards from scratch and relocate the drivers in the front. Second thing to take into account is that a mediocre mid-bass driver that has a very rigid mounting to the door and very good insonorisation will always sound better than an outstanding driver with no insonorisation and bad mounting. The expensive drivers are generally the ones that need a lot of care to give their best. Third thing is that the signal coming out of the OEM head-unit is in all cases crap (even in higher-range OEM units). When I say crap, I'm reffering to both digital-to-analog conversion and amplification. A good amplifier will give you better dynamics having a good damping factor but will also amplify the errors in the conversion made by the DAC found in the OEM source. This being said, among the 2 sets of speakers reffered above, my personal tastes always go towards Focal. Hertz left me the impression of a sterile and dead sound. Focal makes excellent mid-bass drivers but their tweeters (including the old Utopia) are very aggressive and sibilant. The new topia beryllium tweeters are much better for those who have the budget. Other good drivers would be : DLS, Dynaudio, Peerless & Scan-Speak (home drivers at their origin), Brax and Micro Precision (these are the best in the world in my opinion and I've listened to quite a few) !