I'm afraid won't be much. Check Kelly bluebook site & run the numbers. That will tell you & is what the dealers use as a guide.
A 1881 VW Rabbit convertible would be worth its weight in gold; however, I believe you are referring to a 1981 VW Rabbit convertible which is worth far less. In *perfect* condition, with the right buyer, and low miles, in a good economy, and diesel its worth about $3k. In good condition (diesel) its probably worth $1750. In great condition (gasoline) it should be worth $1000. In fair condition $500.
There is no 1991 VW Rabbit.
They are worth anything between $1,500 in poor condition, and upwards of $10,500 or more in excellent condition. Check e-bay, or craigslist to see examples.
Nothing!
1000 miles
About $4,000
a lot
The recommended spark plug gap for a 1981 VW Rabbit is .028"
Less than $4! Just kidding! ;-p
$800
Why do you even care?
More than its worth