Does anyone know why the left rear tire would be going bald on the inside? All of the other tires are good. I don't know if it's been rotated before as this is a new car to me.

Thanks

 

Usually it means too much negative camber for that side assuming the tire has not been rotated from the other side or fronts.

Usually stock camber is not excessive especially for the front. Once you lower the suspension then rear camber can be about -2.0 degrees or more which could wear the inner tread edge over time.

Normal street driving will not cause this wear on one side in the rear. Front wear tends to be on the outer tread edge not inner edge.

You'll probably need to do an alignment and get everything to stock spec settings for best wear.

Inspect the suspension parts and compare right to left in the rear for anything that looks broken or worn out like the shocks, springs or rear control arms.

Inspect the rim for any damage and make sure the wheel fits correctly.
Inspect the tire for any damage to the roundness or sidewall.

 

I'd check your left rear inside brake pad if I were you...

 

It would depend on how many miles, but if it were just the one rear I would suspect that there is excessive toe out on that wheel. This would be an adjustable alignment spec. Too much negative camber could cause it to wear uneven but it will not be anywhere near as drastic as the toe angle. I would take it somewhere to have it four cornered aligned (some places typically only look at the front) before buying any new tires.

 

too many left handbrake turns in the past?