This may be a sign that you need to walk away from these dealers. The 280SS may not be as common as a 280DA. . .but there are a fair number of them out there (or at least *were* out there two years ago).
If the dealer is a totally PITA during the purchase phase. . .I can assure you that the relationship won't improve post-purchase.
If the dealer is a totally PITA during the purchase phase. . .I can assure you that the relationship won't improve post-purchase.