I just purchased a 2001 300M. Only 57000 miles on it so thought it would be great for my daughter. I was driving it home and everything was great, then the check engine light came on - stopped to check the manual to see what the light was and continued on. Another 10 miles and as the car downshifted, the transmission disengaged. I was in cruise mode at the time. No forward, no reverse, no manual shift. The only thing I discovered was that if I shut the car off and turned it on again it would engage in drive as long as revs did not exceed 1000rpm and I could crawl forward. I have a hard time believing the tranny went out at this mileage and we had checked fluid levels before leaving (slight discoloration of tranny fluid but good level and no smell)- no noise, nothing. Any suggestions? The engine codes pulled were P1384 (battery) and P0700 (tranny).