My 8 needs new wheel hub bearings..
 

I honestly don't know much about cars when it comes to that kind of stuff. I gave it in for service because the tires were making noises when slowing down and it was pretty shaky when driving/slowing down. They told me it needs front wheel hub bearing and I have no idea what these are lol. Will these fix the problem or they just wanna get rid of my car already? They had my car for 4 days and only today did I get this diagnostic.

I wouldnt worry about it, if I were you. If it is covered by them then just drive the car and hopefully the problem will be solved. They tend to be able to fix problems like this and if worse comes to worse they can prolly just get another wheel/wheel-well for you. Let us know how it turns out.

Are you sure it is the wheel and not the brakes or calipers?

Wheel Bearings are what make the front wheels (& rotor) turn when connected to the A-Frame.

Your symptoms could be bad wheel bearings -- just have not heard that being an issue before on the RX-8.

You don't have a history of driving regularly through sand or standing water, do you?

Or possibly taking 90 degree corners at a high rate of speed, eh?

What wheels are you using? Stock or aftermarket? If aftermarket, what are the specs - especially offset?

Reason I'm asking - lower offsets than the stock 50mm increase loads on the hubs and bearings. Lots of people here seem to like going to offsets in the 3x range - IMHO, that's too great a change from stock, and we should expect to start seeing some premature bearing failures from people running aftermarket wheels with significantly lower offsets.

Regards,
Gordon