Hi, How do I tell the difference between a "516457" and "516458" chassis on a '91 Volvo 740? I'm trying to shop for a replacement tail light lens online, but don't know which one to get. One site said the number is on the doorpost, but the only thing there is a sticker saying to get the airbag serviced by a certain date. Could it be somewhere in the VIN number? Thank you.