It does appear as though the only option for SSc4.3 in the AGMBC is for alternative fueling stations. Although I don't know definitively why this is, I assume it is so that the appropriate number of preferred parking spaces get allocated to each building, which is exactly what you are indicating is difficult for your project. A few thoughts...if you know how many spaces are required for your site and that is a specific number, can't you pull out how many spaces are required for each building based on occupancy, SF, building type or whatever other variables determine the required number of parking spaces for your site? I understand that this may be a more long-winded way to get to your desired end result, but I assume your number of parking spaces is based on some requirement that can be attributed to each building. Also, it seems that this is required based on no option for an aggregate submittal being offered in the AGMBC. If you are locating some parking spaces in preferred locations for each building, how are you determining how many go to each building? I'm sure there is some opportunity for alternative compliance here as you are meeting the intent of the credit, but you may have to confirm your approach with the USGBC/GBCI or be ready to make revisions to your approach and do some additional work through the design review process.