Try to fix this places.
The first image, in the down place ,you cant hace a lot of edges going to the same point. Follow the edges that goes up and down . In the handle you must have 4 (quarts) vertex not 3(tris), this is the first rule of 3dModel. Always try to avoid 3 vertex. If you use it, only in zones that its not important or not enough visible.
The second imge, in down place, the same error its looks. You have tris, bad. The "blinking light" same error, not tris. The wheel arch need more polygons. Try to fix this too.
In the wheels you have the same problem with tris.
I hope that you can improve with this tips