The connector should be under the dash...usually just to the left of the steering column. You don't need a laptop, an inexpensive reader off the Internet will do the job. Get one that allows you to reset the fault code.
I opened the bonnet of my Roadster yesterday.....compared to my Sigma it is a mass of wires, sensors and pipes
Have you looked under the spare wheel?
More stuff there, no idea what most of it does, but I suspect to do with emission controls....
Will search out the OBD connector, agree all we need is to read and then delete the silly ones. I sent a message to Henry Williams and he said that the 3L Roadsters have far too many error code possibilities, including one if you over fill the tank....Doh!