ouch...im sorry to hear that...man..uhmmm..ok..the limp home mode is defense mechanism that kicks in when there is an internal/external malfunnction in regards to the tranny..so the spoiler motor has nothing to do with that..thats like replacing an engine because gasoline fuel light came on..it makes no sense...all the esp does is lock the rear wheels, it may be connected to the tranny..but i seriously doubt it, however i dont know because this is a mercedes benz we are talking about.so this leaves us with the sensor and pump...but you know what i will call my dealership tommorow and asked the mechanic what he did exatly and instruct on how to do it....but i think u got something wrong now that is not major( because the car runs after re-instaling the battery), but its not to be overlooked beause the problem persist and and keeps coming back, i did some research on mbworld forum, and the slk is notorious for random limp modes...don't worry, im sure it wont be a super expensive repair....ur car will be fine....is ur check engine light on, if so tell the dealer to make it dissappear by deleting the code that initiate it....disconnect the battery for a longer time..on ur instrument cluster, which lights are on....???