diff --git a/src/07_mongoengine/service_central/nosql/car.py b/src/07_mongoengine/service_central/nosql/car.py
index e8120e0..886b78b 100644
--- a/src/07_mongoengine/service_central/nosql/car.py
+++ b/src/07_mongoengine/service_central/nosql/car.py
@@ -2,6 +2,7 @@ import uuid
 import mongoengine
 
 from nosql.engine import Engine
+from nosql.servicehistory import ServiceHistory
 
 
 class Car(mongoengine.Document):
@@ -12,7 +13,8 @@ class Car(mongoengine.Document):
     vi_number = mongoengine.StringField(
         default=lambda: str(uuid.uuid4()).replace('-', ''))
 
-    engine = mongoengine.EmbeddedDocumentField(Engine, required=True)
+    engine = mongoengine.EmbeddedDocumentField(Engine)
+    service_history = mongoengine.EmbeddedDocumentListField(ServiceHistory)
 
     meta = {
         'db_alias': 'core',
diff --git a/src/07_mongoengine/service_central/nosql/servicehistory.py b/src/07_mongoengine/service_central/nosql/servicehistory.py
new file mode 100644
index 0000000..5cc41f2
--- /dev/null
+++ b/src/07_mongoengine/service_central/nosql/servicehistory.py
@@ -0,0 +1,10 @@
+import mongoengine
+import datetime
+
+
+class ServiceHistory(mongoengine.EmbeddedDocument):
+    date = mongoengine.DateTimeField(default=datetime.datetime.now)
+    description = mongoengine.StringField()
+    price = mongoengine.FloatField()
+    customer_rating = mongoengine.IntField(min_value=1, max_value=5)
+
diff --git a/src/07_mongoengine/service_central/service_app.py b/src/07_mongoengine/service_central/service_app.py
index 52b3f8c..3454956 100644
--- a/src/07_mongoengine/service_central/service_app.py
+++ b/src/07_mongoengine/service_central/service_app.py
@@ -1,14 +1,23 @@
 import nosql.mongo_setup as mongo_setup
 from nosql.car import Car
 from nosql.engine import Engine
+from nosql.servicehistory import ServiceHistory
 
 
 def main():
     print_header()
     config_mongo()
+    # update_doc_versions()
     user_loop()
 
 
+# noinspection PyProtectedMember
+# def update_doc_versions():
+#     for car in Car.objects():
+#         car._mark_as_changed('vi_number')
+#         car.save()
+
+
 def print_header():
     print('----------------------------------------------')
     print('|                                             |')
@@ -28,7 +37,7 @@ def user_loop():
         print("Available actions:")
         print(" * [a]dd car")
         print(" * [l]ist cars")
-        print(" * [f]ind car")
+        print(" * [p]oorly serviced")
         print(" * perform [s]ervice")
         print(" * e[x]it")
         print()
@@ -37,10 +46,10 @@ def user_loop():
             add_car()
         elif ch == 'l':
             list_cars()
-        elif ch == 'f':
-            find_car()
         elif ch == 's':
             service_car()
+        elif ch == 'p':
+            show_poorly_serviced_cars()
         elif not ch or ch == 'x':
             print("Goodbye")
             break
@@ -48,7 +57,7 @@ def user_loop():
 
 def add_car():
     model = input("What is the model? ")
-    make = 'Ferrari' # input("What is the make? ")
+    make = 'Ferrari'  # input("What is the make? ")
     year = int(input("Year built? "))
 
     car = Car()
@@ -67,7 +76,14 @@ def add_car():
 
 
 def list_cars():
-    print("TODO: list_cars")
+    cars = Car.objects().order_by("-year")
+    for car in cars:
+        print("{} -- {} with vin {} (year {})".format(
+            car.make, car.model, car.vi_number, car.year))
+        print("{} of service records".format(len(car.service_history)))
+        for s in car.service_history:
+            print("  * ${:,.0f} {}".format(s.price, s.description))
+    print()
 
 
 def find_car():
@@ -75,7 +91,44 @@ def find_car():
 
 
 def service_car():
-    print("TODO: service_car")
+    # vin = input("What is the VIN of the car to service? ")
+    # car = Car.objects(vi_number=vin).first()
+    # if not car:
+    #     print("Car with VIN {} not found!".format(vin))
+    #     return
+    #
+    # service = ServiceHistory()
+    # service.price = float(input("What is the price? "))
+    # service.description = input("What type of service is this? ")
+    # service.customer_rating = int(input("How happy is our customer? [1-5] "))
+    #
+    # car.service_history.append(service)
+    # car.save()
+
+    vin = input("What is the VIN of the car to service? ")
+    service = ServiceHistory()
+    service.price = float(input("What is the price? "))
+    service.description = input("What type of service is this? ")
+    service.customer_rating = int(input("How happy is our customer? [1-5] "))
+
+    updated = Car.objects(vi_number=vin).update_one(push__service_history=service)
+    if updated == 0:
+        print("Car with VIN {} not found!".format(vin))
+        return
+
+
+def show_poorly_serviced_cars():
+    level = int(input("What max level of satisfaction are we looking for? [1-5] "))
+    # { "service_history.customer_rating": {$lte: level} }
+    cars = Car.objects(service_history__customer_rating__lte=level)
+    for car in cars:
+        print("{} -- {} with vin {} (year {})".format(
+            car.make, car.model, car.vi_number, car.year))
+        print("{} of service records".format(len(car.service_history)))
+        for s in car.service_history:
+            print("  * Satisfaction: {} ${:,.0f} {}".format(
+                s.customer_rating, s.price, s.description))
+    print()
 
 
 if __name__ == '__main__':