The Mercedes-Benz R129 SL is on the cusp of collector status. Fellow GCFSB contributor Andy McCulley was in Washington, DC this week for a conference and we hung out a bit during the weekend, with much car talk on the agenda. After passing an SL500 Silver Arrow parked on the street, he opined that that is one R129 that will be worth money in the near future. I don’t doubt it. Few of them were built, with only 100 SL600s receiving the Silver Arrow trim. This SL600 for sale in Massachusetts might not be a Silver Arrow, but the V12 models are certainly more exclusive than their V8 siblings, with this car’s Designo trim adding on an extra serving of exclusivity.