Thank you all for the advice

... I'll definitely stay at arm's length from the Quick Lube guys from now on...
To Junkno: Extremely useful photo album, and funny as well

... That is exactly what I needed (er... do you have one on changing the oil and the ol filter?

).
I have a question about screwing in the plugs and the torque spec, though. I thought I could do that by hand and then twist the plug around a bit with a ratchet to tighten it a bit. However, you underscore the importance of being precise about the amount of torque used, and therefore one would need a torque wrench for that.
However, the torque wrenches I've seen online (I did a search since I was unfamiliar with the tool) are rather on the expensive side of the spectrum. Paying someone else to do the job would be less expensive
Can I do that with an ordinary ratchet and an appropriately sized socket? Or is that too risky?
Edwin