The rear plugs aren't that bad, even the deepest one. You'd have to be massive in the arms not to be able to snake your way in there. Remember to disconnect the battery, and don't remove more than one wire at a time, and you'll be fine.
You should also do the air filter, fuel filter, and supercharger oil. Pump some grease into the fittings on the rear suspension. Some people change the brake and steering fluid yearly. I haven't done mine yet but mean to.
The Sweet Project Cars YouTube channel is full of detailing and maintenance tricks.