The "Make" item is a list of dictionaries, so you just create a new dictionary with the appropriate keys, and add it to the list. Similarly the "Honda" item is a list of dictionaries, so you can add more models to its list. However, "Toyota" and "Kia" are simple dictionaries rather than lists so you would need to convert them to lists in order to add more models.
You can use the code below to help see the structure of the items:
print('\n Keys:', sampleDict.keys())
print('\nMake[0]:', sampleDict['Make'][0])
print('\n Toyota:', sampleDict['Make'][0]['Toyota'])