My BMW has 60k miles on it. It is gradually taking longer and longer for it to get into 1st gear from Park. It now takes about 5 seconds and in the winter sometimes 8 to 10 seconds. Based on other forums I think the ATF is low also I looked into the Automatic Transmission Fluid container in the engine compartment and it is at the "minimum" level. Should I just top it off (if so which ATF fluid should I use) or should I have an indy shop change it for me?