How to get content picker data in surface controller

//Add NestedContent Picker

var nestedContent = content.GetValue("CarDetails").ToString(); var json = JsonConvert.DeserializeObject<>

I get this results.

[ { "key":"51799b8d-0f87-4b9e-a52e-a80f99dbc51b", "name":"Body Type", "ncContentTypeAlias":"carDetailsComposition", "chooseCarDetails":"umb://document/ac0a00738fbb43d3b6ebd01928d61051", "carInfo":"SUV" }, { "key":"39edc3f8-4bec-4752-86d9-4adcfdcb1297", "name":"Number Of Seat", "ncContentTypeAlias":"carDetailsComposition", "chooseCarDetails":"umb://document/53d62b4d52d2414fb0882d263cfd6e85", "carInfo":"5 Seats" }, { "key":"a1414922-4f93-4fa3-91e0-097a6b84d664", "name":"Acceleration", "ncContentTypeAlias":"carDetailsComposition", "chooseCarDetails":"umb://document/1ac2dc8fc40a4d2f97f25c3277b58d07", "carInfo":"9.2 sec" } ]

please help me how to get data from "chooseCarDetails":"umb://document/1ac2dc8fc40a4d2f97f25c3277b58d07".This is singel content picker.