Question: since I will be using the car2_v2.01_hijack.upgrade upgrade file, is it still necessary to apply the 'hack'? Or is it already incorporated in the car2_v2.01_hijack.upgrade file?
I don't know whether it's incorporated (I suspect not), but, unless Mark chimes in and says for sure, you should plan on applying the set_empeg_max_fid hack anyway. It doesn't do anything any harm to attempt to "re-hack" a player that's already "hacked".
Or in general, does anybody have any general tips or remarks concerning the upgrade process?
The steps you describe are definitely the "normal" way to do the upgrade: the most straightforward and least error-prone. There are
faster ways (in theory you can get the full disk bandwidth, upwards of 10Mbytes/sec, instead of 800Kbytes/sec over Ethernet or 400Kbytes/sec over USB1), but they're much more involved.
Peter