The Importance of Servicing

We have a heap of Hyundai Accent's coming through the workshop at the moment from a car yard. All ex rental ones and all have had around 43 000km on them so far. The last one last night had 58 000km on it and when one of my staff pulled the sump plug out to drain the oil nothing came out. We looked in and it was completely blocked with sludge. He prodded it with a screw driver and some oil came out and then it blocked up again.
We have had this trouble before with ex budget camrys so we pulled the sump off.
To our amazement the pick up section of the sump was full to the top with sludge. Only a small hole for the oil pick up tube to go in. We were dumb founded. We cleaned it out and have it and the pick up soaking over the weekend. We will pull the valve cover off on Monday morning and clean it as well before putting it back together. It will come up OK but the engine life will be dramatically reduced.
We can't under stand how it was still running.
These vehciles have never been serviced. This one had a sticker on it for the next oil change due at 10 000 km.
It goes to show how important it is to give your vehicle no matter what brand a service and use good quality oil in it.
I have been a mechanic for 20 years and never seen anything like this before.
Cheers
120scruiser