Lots of people mention the subject, but maybe it needs it's own thread.
Change your gear oil to synthetic as soon as you can. I used Mobil 1. One gentleman (he inspired me) used Redline. It might be better but its hard to find, here.
Keep the car level (no ramps, you can reach the drain) and drain every drop of the old oil. Mine only has a few K miles on it. Since my car is lowered, I needed my skinny son to get at the drain plug. Don't lose the washer!
You'll need a long a$$ funnel. Then dump in that Mobil 1.
I think the owners' manual is wrong in the capacity. It calls for 3.75 quarts. I used 4.
Then go for a drive and be prepared for a seriously dramatic change in your shifting and transmission behavior. It's hard to believe it's the same machine.