You're better off knowing what the repair/total breakpoint is today. Probably a simple calculation to figure out what it'll be next year and beyond. It'll go down, not up. It will help you decide whether or not to carry comp and collision. Do you really want to pay $600 a year for comp and collision with a $500 deductible only to collect $2000 from a total loss when a fender and door get hit? These numbers are made up but probably not unrealistic. www.kbb.com says that the retail value of an 83 300D with 140K miles is $2450. You can't buy a nice one for that much money but run-of-the-mill policies are based on schedules like kbb.com, not market value.

Then again, if it's your only car...

Sixto
95 S420
91 300SE
87 300SDL
83 300SD