Hi,
You may have to do the reset procedure a few times. You might want to invest in a good scanner, I use a Launch CRP 123 it's not that expensive, but it works well. If you have a place like Auto-Zone scan it, they may have to scan it as a 2003 Mercedes-Benz SLK 320 (R 170 Chassis). That is the car that our Crossfires are built on.
The electronics on these cars are very finicky. When a battery is low all kinds of things can happen. The spoiler going up is a dead give away that the battery is low. Also, you should take it on a long drive about 30 miles or more. Since the battery was replaced, sometimes the cars need to re-learn their programming.
Keep us updated, and good luck!