Unfortunately, no. Travel insurance companies don’t cover anything that is stolen from the car or destroyed in a collision –  just the car itself.
Specifically, most travel insurance policies read like the following with regards to car rental coverage:
The insurer will pay the lesser of:
(a) the cost of repairs and rental charges imposed by
the rental company while the car is being
repaired; or
(b) the Actual Cash Value of the car
Up to the maximum limit shown on the insurance policy’s schedule subject to the policy’s deductible.
The exclusions in a travel insurance policy typically list personal possessions as not being covered with the (often optional) rental car coverage.
If your rental car is broken into in a ‘smash and dash’, you’ll be responsible for the loss of anything stored inside it. This is true as well for anything destroyed in a collision. Read the full details on car rental collision coverage and who offers this with their travel insurance plans.
