I am between 5'8 and 5'9 and I have a measured 38 inch chest with a finger in from the measuring tape. I have a 38R suit and 38S sports coats and they both fit EXACTLY the same. However, when I drive, the shoulders feel tight and snug on the jacket. I drive a stick and it's kind of difficult because I don't want to ruin my suit jacket. Also, when I wear my cell phone in a holder on the side of my hip (belt clip) and button up my jacket, you can see the shape of it faintly but not when it's unbuttoned. These suits don't SEEM to fit tight...but I was wondering if you guys have any tips on how to test how they fit when they sit good on my shoulders and my arm length is good, to know how "flexible" that it should be for things like driving, etc. Thanks! PS A 40, a size up, seems too loose by a long shot.