I havent seen your listings on your problem but the speedo hole should have nothing to do with it,most transverse gearboxes are filled the same way they dont have a filler cap as the engine has.Put the car on level ground,on the front of the gearbox about halfway up the casting will be a large hexagon headed nut loosten the nut and oil may drip out of it (you have the right nut)it is only a short thread on it and will be very loose to the touch when you unscrew it.You fill it by buying gearbox oil in a plastic bottle with a clear tube on the top they are standard bottles,bend the tube into the hole and squeeze gently until oil runs out of the hole,that is the level of the oil.If a lot of oil spills out when you loosten the nut off then there was to much in in the first place.Why do you think you need some in anyway?it doesnt burn it or loose it unless you have an oil leak that needs fixed.Good luck.
Rich
September 2007