Here's a post to get back on the right track!
I don't know if I've done much more than normal summer maintenance, but I like to get done what I can in warmer weather since I don't have a garage, and with down time it's been a good distraction. I don't have a C5 but on my C6 I changed the oil, changed the clutch and brake fluid with DOT 4, re tightened and torqued the exhaust clamps, greased the outer rear sway bar links, checked the transmission and rear differential gear oil levels then figuring out how to change it when needed, changed the battery when it died, and painted the brake caliper red. The drain for the rear differential on the 2005 is partly over top the leaf spring so you can't fit a 10mm allen socket but was able to fit a 10mm allen wrench, put a box wrench around it for extra leverage, and break lose the drain.
On My G35 I changed the oil, replaced the piston dust boots on the front brake caliper as one had torn over the winter, so I replaced the slider pin boots while I was at it, repainted the front brakes red since my original painting was thin from running out of paint, lubricated the front and rear sway bar bushings, changed the power steering fluid (never done), cleaned and reoiled the air filter, and cleaned the MAF (never done). The car has polyurethane bushings, they squeak on bumps since I've had the car, I've tried using silicon spray which would partially work, so this time I removed the bushings, cleaned, lubed, and reinstalled.
