Hi, welcome to HAN

The whistling/humming sounds like a bad alternator. They cost abour $120-$200 on ebay and it's a pretty easy do it yourself job. It's a very common problem on the V6 model...they're made by Delphi. Try a search on that.

The transmission is also pretty normal. Sadly, we got some pretty shitty transmissions in our cars - you can find a discussion about it in the FAQ. Your best bet is to drive your car until it dies and then get a slightly used or rebuilt tranny on ebay. Mine died at 150k, I bought a 33k old tranny on ebay and now at 191k miles (74k tranny miles) it's still working well.

Chris