It looks like after 25 years you don't even need to have it registered as an antique, and after $680 you can indeed apply for a waiver.
http://www.dmv.org/va-virginia/smog-check.php
Like many states, Virginia requires most vehicles to be up-to-date on two separate types of tests: one for emissions, and one for safety.
Emissions Inspections
Certain areas in Virginia require your vehicle to pass emissions inspections every two years. The most a smog check can cost is $28, which includes one free retest within 14 days if your vehicle fails the first time.
Exemptions to the emissions inspection requirement include:
New vehicles being titled for the first time in Virginia with a manufacturer's certificate of origin.
Gasoline-powered vehicles 25 years old or older, whether registered as antique or not.
Diesel vehicles.
Vehicles exclusively powered by clean fuel.
Certain hybrid vehicles.
If you are required to have an emissions inspection, it must be done before you register your vehicle. When registering, if you cannot show proof to the DMV that your vehicle passed the emissions inspection, the DMV can issue a one-time-only 30-day temporary registration. This will allow you time to get your vehicle to pass inspection.
When your vehicle's registration renewal notice indicates that a smog check is required before renewing, remember to take your renewal notice with you to the inspection station. It will speed the process.
Comprehensive information about Virginia's emissions testing program is available from the Virginia Department of Environmental Quality (DEQ), which administers the program. Here you can also search for an inspection station near you.
Waivers
If your vehicle fails an emission test, you must take it to a garage for emission-related repairs. The garage must be certified by Virginia's DEQ.
If your vehicle fails again and you paid $680 or more in emissions-related repairs, you will qualify for a waiver. The emissions-testing facility will provide you with the paperwork to apply for a waiver.