There is no additional premium imposed for an unnamed driver in this category to drive your car.
Often, most insurers will not want you to add a young, old or inexperienced driver into the policy. However if you are allowed to, additional premium is required. This may range from a couple hundred to almost a thousand dollars.
All insurers impose additional excess (usually between $1,500 to $3,000) for young, old or inexperienced drivers who wish to make claims under your policy.
The typical definition of a young, old or inexperienced driver is as follows:
a. Young drivers: Below 27 years old
b. Elderly drivers: Above 65 years old
c. Inexperienced drivers: Less than 2 years driving experience (with respect to license pass date)
Please note that the figures above differ from insurer to insurer.