Duty on car?

Hello,

I like to bring my car to DR, but I've been told that we have to pay duty at the custom, and I've been told that if the car is more then 10 years old, there is an additional tax (fee)!

What I like to know is, if someone can tell me what is the exact tax for the Duty and the extra fee for an older car (if there is any!).

Here is the information of my vehicle:
1990 - 300ZX Nissan, non turbo.

Thank you.