How to use "args" as JSON instead of array of strings (i.e. [] string )

[mna2016]

Hi All,
I am trying to modify the chaincode vehicles.go in order to have "args" parameter of an incoming invoke statement as a JSON instead of array of string. I want the request to look like below:

{ 
	"jsonrpc": "2.0", 
	"method": "invoke", 
	"params": 
		{ 	"type": 1, 
			"chaincodeID": 
	        { "name": "fe4ffc3aff02c2dda7a61f18d934c84474edecd4fe1ade6c5181f541afd936bff01bc6b3066f349b5caed6aa0f1a74e31d47ee82929d3157194f441afa171ff2" }, 
			"ctorMsg": 
						{ 
							"function": "update_xxx", 
							"args": {"make":"HONDA", "vin":"MOD123", "color":"RED", "owner":"DVLA"} 
						}, 
	"secureContext": "WebAppAdmin" 
		}, 
"id":1234 
}

1. How to update the vehicles.go in order to achieve this?
2. Is there any other place where I need to make change in order to accept this new invoke API call structure?