My son's got a third party reader for his Skoda - it's a copy of the VW one. It can do all sorts of stuff. He's altered the throttle response, activated the 'clock sweep' on the dash on start up, tweaked his alarm and so on. He's fitted an induction kit in the last week, which means you can hear the turbo spin up more.
I keep thinking about a fault-reader/re-setter
My Octavia's well over 9 years old (June '11 registration, I bought it in March '12)
It's still garage serviced, as it was yesterday
(crikey, that synthetic 5W/30 oil's expensive!!)
Granted yes, I could do the oil/filters myself, but there'd still be the service light illuminated
Plus, there's the peace of mind, that as I ask them to road-test it, they make pick up on an issue that I've not noticed - due to sheer familiarity (maybe due to simple 'wear & tear')
We've used the same garage for over 6 years now, so we trust them
(they also look after wifes C-HR, & daughters car too)