HISTORICAL DNA evidence has linked a 2004 Warrnambool car theft to a rape near Naringal in 1988.

Cold case unit police at Melbourne's sexual crimes squad have appealed for the public to help identify a man, who would now be aged in his late 40s or early 50s.

Police said on December 26, 1988, a 21-year-old woman left the Lady Bay Hotel at 9pm before accepting a lift from a stranger at a Raglan Parade intersection.

The man then drove her to a deserted area, reported at the time as Naringal, and assaulted her inside and outside the vehicle while threatening her with a knife.

He was described at the time as aged between 20 and 30, between 170 and 180cm tall, Australian in appearance with dark complexion and dark short hair.

On October 25, 2004, a green 1985 Holden sedan was stolen from Warrnambool's Merrivale Drive about 9.30pm.

It was found the next day on Wangoom Road in Framlingham, containing DNA recently determined as a match to a sample taken after the 1988 rape.

Detective Senior Constable Penny Crossley said while someone may not be prepared to come forward over the car, police hoped the link to a sexual assault would persuade someone to identify the offender.

"Obviously both incidents are 16 years apart and, while DNA alone does not prove guilt of two offences, it shows the same person is linked and that person is certainly now a person of interest," she told The Standard.

Warrnambool police originally released information on the rape crime on January 13, 1989, telling The Standard the offender gave the name "Colin", had a medium-build, a wispy moustache and had the appearance of a "petrol head".

At the time, police said the assault took place in the Naringal area about 2am on December 27 and described his vehicle as a Falcon XA or XB.

With advances in DNA technology, in 2011 the sexual crimes squad began re-examining almost 300 cases, with priority given to the worst 20 cases that involved abduction, aggravation and weapons.

Since then forensic scientists have pored over the original evidence looking for fresh clues, solving 35 cold cases in the past three years.