ive been telling him that for awhile now i gave up lolI think you were always good. The only advice I have for you is to start working on the backgrounds a little more. There are some pictures that look great strobed in the dark and you have to keep in mind there are shots that look great strobed during the day. Your lighting is always very good, but your backgrounds are always dark. Start expanding you horizons and get those awesome skys during the day into your shots!
and the sti shot looks great, but maybe alittle more light on top of the hood/right side of the car.
and also try cropping it alittle more from the left side. cars seem to look better when they are the same distance from the left or right, and the bottom of the pic