For antique auto insurance that is generally written for "stated value" (usually the amount the insured requests, perhaps backed up by an appraisal) and is sold at very reasonable rates, it can be a huge, costly mistake to underinsure the vehicle. What happens frequently, however, is that the owner insures the LBC for the amount he pays for the car. Over the course of a few years, he/she does some restoration (paint, body work, engine rebuild, etc.) and the car appreciates anyway, but the owner fails to increase the stated value. Just like your home insurance, so should evaluate the coverage on renewal. For me to increase my coverage by $2000 would only cost about $14 a year. That's cheap insurance.