I'm looking at a 2010 se 5 speed with 20K miles. I took it for a test drive and it felt great, except at idle every once in a while the rpms would dip just slightly (to about 550 or 600). I was wondering if this was common amongst 2010s or if I should have it looked at before purchasing. As well are there any other common problems with foci of the year that I should be on the look out for?