https://api.edmunds.com/api/vehicle/v3/makes?api_key={api key}

{
  "totalNumber": 66,
  "totalPages": 7,
  "results": [
    {
      "id": 200347866,
      "name": "Geo",
      "niceName": "geo",
      "adTargetId": "geo",
      "niceId": "geo",
      "useInUsed": "Y",
      "useInNew": "N",
      "useInPreProduction": "N",
      "useInFuture": "N",
      "models": [
        {
          "id": "Geo_Prizm",
          "name": "Prizm",
          "niceName": "prizm",
          "href": "/api/vehicle/v3/models?id=Geo_Prizm"
        },
        ...
      ]
    },
    ...
  ]
}