Need Some Advice

[sharocks]

Hey all, long time lurker, first time poster.

So I have had my 05 4.8iS for about 2 years now. Bought it at 70k now just crossed 102k.

Love the car, however it is starting to have some issues. Particularly with the transmission. It seems to be slipping while driving especially in automatic mode in higher gears. 5th is the worst. I actually skip over it since I only drive the car in manual mode.

So my question, what happens is this situation? Any ideas for a fix? Used transmissions aren't too bad but I don't want to deal with this issue again.

Any help is appreciated since I'm also considering trading her in for a smaller vehicle if I have to.