Just done my major service 2 weeks ago.

Changed the following:
- OEM NGK iridium sparks
- OEM transmission oil
- Engine oil (Valvoline 10w-30)
- OEM oil filter
- Nulon One Coolant
- Air filter
- Cabin filter

One thing i noticed this time was that this particular service made a noticeable difference! For me anyway.
There was a slight ping under heavy load (as we all know for CU2's) that didn't really bother me. However after this service it has completely gone!!
The engine is much smoother and revs better.

I am thinking 100,000kms for the spark plugs is too long maybe.
I don't think it has anything to do with the motor oil because i used the same oil and filter last change.
I doubt it's the air filter because i have changed that before and didn't notice any difference (it's never that dirty when i change it anyway).
No change to 95 ron fuel used too.

So i am glad the car is even better than it was. As you all know, even after so many years. I still love my CU2!