Tailgate Latch problems of the 2004 Land Rover Discovery

In 09-2004 purchased Land Rover 2004 Discovery, after contacting the dealer and Land Rover csr they informed me that my 2004 has a door checker as a safety device on tail gate door which is sharp and swings closed. Come to find out that this is something else. There is no safety latch for Discovery vehicle tail gate doors-I offered to pay and nothing is available. They said that it is only required to stay open on flat land with no wind. I live in California, redwood shores where the whole town is flat and the weather is mild this door has almost killed me twice. I feel this car does not comply with safety requirements for this reason.