[86TOYO2k17]

spark plugs are actually super easy to do IF you jack up the engine, you literally only have to remove the lower undertray and then 2 bolts (1 for each engine mount) jack up one side at a time to angle the engine, you can jack the engine up using an 8" 2x2 jacking from the engine mount, (I nailed the 2x2 to a 1" 4x4 and nailed 2 side supports to make sure it didn't fall off the jack) place the 2x2 on the bolt on the engine mount to block and jack it up.

Passenger side remove ECU from fuel rail cover and move out of the way and remove fuel rail cover
Driver side unclip / zip tie fuel lines out of the way
Remove fuel rail covers. remove any strut bars.
Put car on stands
Remove undertray
Remove the one bolt from engine mount to cross member on both sides
Jack engine up one side at a time from the exposed bolt head going from engine mount to engine using the 8" 2x2" (jack extension mentioned above)

Now you have all the space, clearance, and visibility in the world to easily remove the coil packs and spark plugs. I changed each side in under 10minutes going slow triple checking everything, you now have space to use a torque wrench for proper spark plug torque specs.

Once completed reveres the steps, and done. can be 100% done on and off stands etc... easily taking your time triple checking everything, properly torqueing every bolt top to bottom in under 2 hours.

Jacking the engine up adds roughly 20minutes of time to then save you well over an hour, make the job 10x easier, and also saves your hands from any scratches.
I see zero reason to not jack the engine up unless you don't own a jack and stands. in which case go buy some.

If changing engine mounts, you can jack the engine up using a block of wood on the oil pan, however for spark plugs you want to create extra clearance by angling the engine so doing one side at a time is better.