[{"model":"Nissan","regId":1230,"status":"active","regCost":100},{"model":"Nissan","regId":1231,"status":"active","regCost":100},{"model":"Nissan","regId":1232,"status":"inactive","regCost":0},{"model":"Honda","regId":1233,"status":"active","regCost":90},{"model":"Honda","regId":1234,"status":"active","regCost":90},{"model":"Toyota","regId":1235,"status":"active","regCost":80}]

db.collection.aggregate([{"$group":{"_id":"$model","TotalActive":{"$sum":{"$cond":{"if":{"$eq":["$status","active"]},"then":1,"else":0}}},"TotalCost":{"$sum":"$regCost"}}},{$facet:{total:[{$group:{_id:"Total",TotalActive:{$sum:"$TotalActive"},TotalCost:{$sum:"$TotalCost"}}}],data:[{$match:{}}]}},{$project:{data:{$concatArrays:["$data","$total"]}}},{$unwind:"$data"},{$replaceRoot:{newRoot:"$data"}}])