I have a 2006 300 srt-8 with 60k miles on it. I got the car in October and its been running great up until last week it didnt start for some reason. It wasnt a battery problem so I let it sit for about an hour or two and tried it again and it started. But ever since that there been a very slight vibration in the peddle and brake around 1500-2500 rpms. I didnt know if it was my harmonic balance going bad or just my tires need balanced. It feels like its getting worse too but I might be wrong. Any help would be great!