What's the best product for me to play my iPod through my car's audio system?

I have a fully loaded 90s Mercedes Benz (but the 6-CD changer is broken and the audio cassette player could go out anytime, so I want to avoid anything that would utilize those. And I have a 2nd Gen. iPod touch.

On Apple’s website, it looks like there are at least 16 companies that sell ‘after-market solutions’ to connecting the iPod with the car’s audio system, and many of those offer more than one product. Target offers a number of other products as well!

Can you help me sort through all the options to find the one that’s best for me?

Edited to add: And I don’t want to spend a fortune. For sure, less than $100, preferably less than $50.