The 280GE and the 460 GD's has the starter on the same side. I think the 230GE has the starter on the other side. If you cant find a G auto box, you can probably use a box from a W123 230E/TE. I am not sure about the W124 ones... Exhaust should not be a problem, the manual and auto box are quite similar in size (NOT in wheight though...)