According to a representative of the North Carolina Division of Motor Vehicles (a section of the NC DOT), offenses remain on your driving record and do not at any date drop off.
The representative stated this includes suspensions, DUIs, accidents and minor violations such as a speeding conviction. So if you were convicted of a DUI in 1999 it will remain on your NC DMV record permanently.
As for your insurance rates, even though in North Carolina your driving record will have the largest impact on your insurance premium you should not receive higher rates for the rest of your life even though this violation stays with you for your lifetime. According to the NC Department of Insurance, insurance points are charged for at-fault accidents and convictions for moving violations that occur within the experience period. The experience period in NC is considered to be the three years immediately preceding the date of application or the reparation of the policy renewal.
To reward safe drivers with the lowest possible insurance rates, the NC General Assembly enacted the North Carolina Safe Driver Incentive Plan (SDIP). Drivers who are convicted of moving traffic violations and/or cause accidents will be charged higher premiums in accordance with their driving records. Driving while impaired comes with 12 SDIP points. According to the North Carolina Department of Insurance this amount of points comes with a 340% increase in your premium rate.
So while your rates were due to be raised due to your DUI offense they should not continue to be rated on this issue beyond the 3 years of "experience period" that the NC DOI notes.
If your auto insurance premiums are still high due to the 1999 DUI you should speak to your agent and find out why and when they will be lower. If you do not get a satisfactory answer you can contact the NC DOI for consumer advice or to file a complaint. You can also shop around for a new auto insurance policy; start here with us by getting a quote from an auto insurance specialist.