> I remember these Macbooks did tend to break apart at the corners of the palmrests.
Not the corners for me, but the "feet" of the topcase digging into the palmrest, which would splinter the plastic, then you'd have holes in the case and jagged plastic splinters digging into your wrist as you typed, not enjoyable.
This: https://ismh.s3.amazonaws.com/2014-02-24-macbook-topcase.jpg is exactly what mine had, on both sides.
Shame because it was the last macbook that was really easy to upgrade: the battery was removable (with a simple lock), and behind it were the RAM and 2.5" drive slots.
The next generation was not that hard but you had to unscrew the entire bottom shell, and the battery was glued.
Unscrewing the bottom on the generations after this gave you access to nearly everything. Which was vastly superior for most repairs. Getting to the logic board or AirPort card on the polycarbonate MacBook took significantly longer. For the Bluetooth motherboard you had to remove the display cable, optical drive and HDD.