I don't think it's possible to upgrade from a LT to an SS without losing $5000 minimum in the trade/sell of the LT and purchase of an equivalent year (same miles) SS. I suspect it would be even more than that to purchase a new SS.
When I say $5,000, I'm not talking about the price difference, I'm talking about the money that you'll lose (profit for the dealership on the back end of both deals plus tax). That's too big a pill for me to swallow but if someone has the extra cash then I say go for it. The only thing is, I'm assuming most people who bought an LT to begin with probably don't have $5K to flush down the toilet.
If you find a way to do it for less, let me know and I might consider it too
