Also have a Hollard MotorExtender policy for my car since Nov 2015 as well.
In July, when my car went in for its annual / 105,000 km service, there were 3 mechanical issues found:
1. Coil pack & HT leads needed replacing (misfire when idling or accelerating).
2. Brake Booster Unit needed replacing (intermittent vacuum boost leak).
3. Water pump, metal coolant pipe & main radiator / heater / expansion tank coupling hose (plus coolant) needed replacing (coolant leak from pipe / hose & noise from water pump).
I claimed for all 3 items & Hollard paid out just under R 11,000 for all these parts, within 3 weeks of me submitting all the paperwork.
My policy is only R 300 a month, so I basically had all my instalments to date refunded with this claim.
So yes, very satisfied with Hollards extended mechanical warranty policy so far.