Chrysler Corp. is increasing its payments for taking test drives in some 1980 cars and vans to $500.

The company had been offering $50 to prospects who took test drives and bought a Chrysler car -- or any comparable U.S.-made car -- within 30 days.

Now if a potential customer tests at a participating dealer the Dodge Mirada, Chrysler Cordoba, Dodge Diplomat, Chrysler LeBaron, the Plymouth Voyager or Dodge Sportsman utility vehicle or a Dodge van, he or she will get $50 for the drive as before.

But someone who buys the car he or she tested gets another $450, Chrysler said.

No expiration date was announced, but the company said it is allowing only one test drive per customer. As in its other current rebates, the money may be assigned to the dealer as part of a down payment.

The guarantee program includes a money-back offer within 30 days and 1,000 miles, free scheduled maintenance for two years and membership in a motor club.

Although Chrysler officials have noted some improvements in sales this year, deliveries remain bogged down well below last year's levels. At the same time, the company is struggling to pull together $2 billion in private financing it needs to qualify for $1.5 billion in federal loan guarantees.