I think that my wife's late 2002 Polo 1.4 SE lasted all of its 105K miles/13 years with her on its original CTS - my old Passat asked for a new one though and daughter's late 2009 Ibiza 1.4 SC has coughed out a duff measurement warning, so when the weather gets warmer ------.
I'm assuming that you have had the ARB replaced, wife's car needed that at about 5 years old, such is the level of salting on Northern roads! I've always used NKG plugs on VWs, it pays to get hold of a genuine spare COP (Coil On Plug) as unless they have been replaced, they will fail one by one, my VAG supplier of choice is Eldor, and if possible an old version before they moved manufacture to Turkey and basically turned these and any other parts they made there into proper turkeys -- a country full of rubbish makers of rubbish parts both genuine and fake!! Fuel filter, I always worried about that, but still have the one I bought for wife's car, so if you are using good petrol places your one should be okay for a while. While talking about petrol, have you ever tried using Shell V-Power Nitro, the high octane stuff, just a warning, if you do, after a couple of tanks you will not want to gao back to normal UL as the improvement in drivability I found to be amazing - which that engine ends!
Other potential issues, the front Lambda Probe heater circuit usually fails about this mileage, again if it does, buy a VW sourced or exactly the same NTK replacement - which ever is the cheaper for you. Next, the EGR valve circuit, the EGR valve itself should be clean and okay, but where the steel bendy pipe enters the inlet manifold, or into an adaptor plate, or into the bottom of the TB (Throttle Body) gets clogged up with the mixing of recycled hot exhaust gasses and oil mist, that will lead eventually an engine fault being logged, it should be related to the EGR gas flow. MAP sensor, it is easy to reach at the driver's side of the inlet manifold and cleaning it by gently spraying it with brake cleaner a few times should help things and maybe stop some of these fuel trim warnings.
If you have not yet done so, buy a Haynes manual and maybe a cheap scan tool - I needed to check clear faults on wife's Polo maybe once every 6 months including incorrect faults due to stupid VAG S/W issues which they denied and so remained.
Does that car have disc brakes on the rear? If so, maybe buy and fit external return springs, also clean all brakes before an MOT as the adverse road conditions will have gunged them up.
Front TCA rear bushes, I had to replace them on wife's car at about 5 years, I got an Indie (Star Performance in Dysart Fife) to fit SEAT Ibiza Cupra solid bushes, that sorted that out and improved the turn-in and they might just out live the car!
Engine cambelts, they should be replaced at 4 or 5 year intervals, mileage limit will not be reached in your case but the belts etc still need replaced to avoid engine destruction, again I used Star Performance at Dysart Fife.
Maybe take a look on other VAG forums for what you can expect and there will be write ups on how to do it, I'm guessing your engine is a BBY.
www.briskoda.net www.seatcupra.net you will need to look in the Fabia MK1 section and the Ibiza 6L sections respectively.
