2010 PT Cruiser - follow up

2010 PT Cruiser, 25000 miles

The oil leak was a bad head gasket, repair under 5 year power train
warranty at no cost to me.
Wonder how long this repair will last?
I thought is was kind of unusual for a low miles car to blow a head gasket.
Repair receipt shows upper gasket set, antifreeze, and oil change.
Also shows a bad O2 sensor and check engine light, which I never had a
problem with.
Bet the tech damaged the O2 sensor tearing down the engine.
Not a problem for me, was covered under warranty.

Was also told the front lower control arm bushings were shot.
That repair was covered by extended warranty with $100 deductible, plus
$99 for alignment. Not too painful.

Receipt shows they replaced the entire control arm / lower ball joint
assemblies, claiming bushings alone not available. A quick look on eBay
shows plenty of lower control arm bushings available. Not a big deal for
me either way, guess the complete unit is only item available in the
dealer parts network or perhaps the extended warranty only covered the
complete item and not bushings only? Who knows?