Some very wise BMW folks here advised me to be patient, and I spent more than two years looking for my car. There are cars out there; I ran into a guy at the Pittsburgh Vintage Grand Prix last month who got a car similar to mine for a whole lot less than I paid.
You will find that under $25k, there are bunch of rusty cars that pop up for sale every three months or so. You need to pass on these. Be diligent, and look at cars that come up for sale in your area (where are you, by the way). Also, you are looking at a bad time of year. The better bargains come around in the winter when sellers have fewer potential buyers.
Finally, remember the number one rule of used cars; evaluate first, then fall in love. Much heartache has arisen from getting this sequence wrong.