That funny, I was going to mention the SPL control arms.
I'd take it to an alignment shop and get everything all squared up like Aud already mentioned, it might also be worth it to buy a lifetime alignment if your local shop has one.
Tire feathering and cupping was an issue with the early 350Z, so much so that Nissan actually released a TSB regarding it. I think some small part of it was owners being unaware of how quickly performance summer tires wear down, but there was some fault on the Nissan end as well - so the TSB.
Welcome to NICO!