I want the door to stay closed while driving down the road and have all the contents stay inside the cabinet. Home Depot and similar places sell latches for cabinets in a house where unless there is a tornado or an earthquake nothing is wrong with a simple magnetic latch. Obviously this type of latch is worthless on a mobile RV.
The front door is mirror with a 3/8" metal trip and no place to drill holes to fasten a latch to it. Odd that the RV industry ignores the medicine cabinets but will do RV targeted plumbing and has done so for more than 40 years.
The cabinet is a corner cabinet or I would be looking at marine supply options. Overall it is a major pain to have a 4-year old Lance camper with no support from the manufacturer. Next camper is not likely to be a Lance.