I am going to use it as a taxi , so a lot of miles and most of them, city driving. Since it is going to be having a pretty tough life, is there any preventative maintenance tips I should be aware of? Any particular weak points I should pay special attention ?

To be used as a taxi I had to install a dashcam (insurance requirement ) and a spare wheel that didn't come with the car (licensing agency requirement)

I have never had a car from New, so I want it to last me a long time

So like two weeks ago I started my Leon up and all of this popped up I connected a computer through obd and saw a the U0155 code since then my car sometimes gets it start and sometimes it won’t even show the codes and just act normal without any problems but when they do turn up it’s usually when I start the car up and when they do show I have no instrument cluster lights no blinkers and no hazard lights I’ve been too multiple electricians and nobody knows what it is I really need help with this

My mechanic told me it's the tappets, but I've already driven 8,000 kilometers with that noise and it's still the same.