100k mi, Engine now makes shake/wobble

[albatrill]

Greetings, I have a 2005 3.0i that just went over 100k miles. When I start it up after a day or 2 of being off, the engine has a wobble / shake to it. It definitely does not sound as smooth as it did. What could this be, and can I do anything myself to fix this?

I'm also looking for a new Amp for the sound system, my whole radio/speakers does not work, the repair place I took it to said the amp shorted out and I needed a new one. They wanted like $600 to fix it, no way I'm paying that. What is the best bet for finding a new one? I'm assuming it cant be too difficult to find one? I also eventually want to get an OEM trailer hitch, so would like to find one of those as well. I live in Austin, TX.

Thanks for any help, I appreciate it!
Cheers.