would using a staggered tire setup be okay for my 2004 G35 Sedan RWD?
 

The tire sizes I was going to use on the back would be 220/55/17 and on the front would be 215/55/17... Would this be fine?

As long as overall tire diameter is less than 3% difference it will work.

As long as overall tire diameter is less than 3% difference it will work.
 

The guy at the shop says he thinks I will feel it when I am driving and that the tires won't be able to get rotated...Im not sure if I should wait it out or what

Well yeah you won't be rotating the tires but what does that matter? Sports cars don't rotate tires because of staggered setups so... ???

Also, what exactly are you.supposed to "feel"? I don't think your tire guy has any idea what he's talking about.

My only concern is it might look wierd on a sedan so be sure to Google up some images of that setup before you purchase.

There are a hell of a lot more knowledgeable people on this subject here than your guy at the shop. I assume you have the stock 17" wheels and yes, those sizes will be fine but why bother with such a small change? If you want a little beefier tire just go with the 220's on all four corners.

235/50/17 front and back work great and are the same diameter as the OEM sedan size so your speedometer will be accurate.

That's ^ a great idea.

NDS2 allows you to adjust tire and wheel sizes so you get accurate speed/miles. Not sure how much of a difference it makes. Never tried it

All I know is according to my GPS, my speedometer dead accurate.