Firstly i would reccomend you get the car looked at pretty soon. It may just be an alignment problem, or could be a little more serious.
I had an issue with my car at about the 30,000km mark, where the clutch cable wasnt adjusted correctly (By kia at time of purchase), causing the clutch plate to never fully be released - wearing out completely and slipping.
This was replaced under warranty after a pretty heavy fight with the dealer i must add.
Hope you get the issue resolved and would be good to know how you go.