1996 SL1, auto trans. Rebuilt once at 40,000, now at 57000 seems that the transmission "slips" when attempting to accelerate. Trans has new filter and new fluid (I assume fluid was flushed at first rebuild). Any suggestions?

You checked the fluid level, I assume. Could be a sticky valve body, clogged filter, bad pump, bad clutch packs or a teeny tiny passage inside the tranny is partially blocked.

you should probelly flush out the tranny anyway becouse you went 17k miles on the fulied that is in there now.