I had a similar idea and the excellent chaps at Allon White knocked this up for me. Their trim expert Shaun is a real craftsman and their customer service is second to none. Not too sure about the handle (folded out of the way in this pic), as I thought it might be a neat way of carrying the (removable, via Velcro) bag when out and about - but it just looks like a girlie handbag in truth, so it may yet have to go....
Anyway, works a treat but might work even better on a pre-gearlever revised car, as opening it when not in 2nd or 4th is less than optimal. Holds phone chargers, earplugs, gloves, that sort of thing. I stuck the Morgan badge on it, but jury is still out on whether it adds much.