http://mobileheads.us/fm-car-transmitter.html
This would make a lot more sense for Pagoda owners, of course, if the radio and speakers we had were worth a darn. Try as I might I cannot say nice things about my Becker Europa MU playing through that single speaker in the dash.
I have also not had good experiences with FM transmitters for playing through car radio. I found that the Becker Europa with single speaker in my W114 250C sounded great. The biggest problem people run into is when they try to change the speakers in favor of larger ones that want more watts.
I have had very positive experiences with the plug-in thing that goes in the back of the becker and has a small box with a input jack that you can place remotely in the car.
As for lack of power, I am (back burner) researching an amplifier replacement - someone is producing a cable that your head unit amp cable plugs into that can be in turn plugged into a "modern" amplifier. I haven't gotten far with it, but it would solve the speaker problem completely.
Audiophiles need either a separate head unit hidden or a bluetooth setup that is hidden. In my "modern" car (2010 Jetta) everything plays through the car audio system via bluetooth, which is extremely convenient as I generally listen to internet radio via my cell phone (tune-in is the app I use).