I live in MA. I have a car that I'm planning on selling. Right now it
does not have insurance or a license plate due to my disabled mother's
license expired & her insurance could not be renewed.

I know the car is in great condition, but buyers are going to want to
test drive it. I want to know how can let the buyers test drive it
when it does not have either the license or insurance? Is there a way
to get a temporary license plate & insurance for this sort of
situation? Thanks for the answers in advance.

I work for an insurance company in Massachusetts. To do things
legally, you will need to obtain insurance and plates. If you find a
reputable Independent Agent, they will be able to help you. If you
take out a policy and somebody purchased the vehicle shortly
thereafter, you should return the plates to the RMV ASAP. If you
cancel the policy in the first thirty days, you will pay a "pro rata"
premium and will not be penalized.
 
In order to take out a policy, your mother will have to turn in her
license to the RMV. She will also have to apply for the policy. You
must be listed as the principal operator and she will be excluded from
operating the vehicle.