I had a gentleman at a transmission shop try to talk me into it... and I said no. I figure that the additives aren't necessary on a physically healthy gearbox.

On my folks' Honda Accord automatic, the 'D' light flashes when the tranny computer encounters an error. In their case, it happened to be new solenoids that were needed. But it also flashes sometimes when there's no problem, once every great while.

I find that automatics shift harder when you're light on gas. If it's a new problem, though, have a tranny shop flush the system or do some other maintenance. I'm sure happy I did, on my trusty (and more all the time) 740GLE.

Ari (SpazMan's my login - but I appear to be Bachelor54!)