so, i ended up going to Sears Auto center, because i had some credits available to use at Sears (including auto services, which i was unaware of), they also seem to have the lowest prices for the 3 stage cleaning.
i asked if they used BG products, going off of SwampRats recommendations, unfortunately (i assume) they used run-rite instead. i told the service manager that my car has a DI, turbo motor; he said that was fine and that their service is fully compatible. he also offered some incentives if i added a coolant flush service, both services out the door for around $140. that was about the same price for just the 3 stage cleaning from the Lincoln dealer. so i went ahead and got it done, with my credits i only paid around $40 directly out of pocket.
after the service i put some Shell gas in, resetted the MPG status and went about my Saturday. i had a lot of errands and went out that night as well. i actually drove nearly 90 miles all together. the MPG meter ended up showing 20.3 MPG, with my normal spirited driving in both city and highway! i was very happy with that figure, because before the cleaning i was getting about 16.6 MPG!
so maybe the car did have some built up carbon deposits that was negatively affecting it. i'll report back on my observed MPG later on to see if the gains hold up...