The UK car population has increased 18% in the last decade, but the number of repairs rose just 1% in the same time.
By comparison, total losses have increased 86% since 1998, and without theft, glass or personal injury these now account for 24% of claims.
SMART repairs have created further downward pressure on work volumes, costing them half a million repairs each year, the report adds.
As a result, the number of bodyshops has declined 36% to an estimated 4,010 and Trend Tracker predicts a shortfall in the capacity from 2010 onwards.
Robert Macnab, of Trend Tracker, said: “The cost will be partly carried by bodyshops themselves, whose insurance company customers insist on them providing courtesy cars, and partly by the at-fault drivers whose insurers face courtesy car bills from credit hire firms, in the form of increased premiums.”