Maintenance on 2008 Cadillac STS

At what point should I get the folowing things done? Rear differential, transmission flushed, fuel induction and Cabin filter?

Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
1 answer
Check the scheduled maintenance here http://repairpal.com/estimator?car_type_id=6291 and you can find a shop here http://repairpal.com/directory?address=92225&car_brand_names=Cadillac