Hi,
The product you linked to seems to only be compatible with certain radio head units (and probably OEM ones at that). This means it might not be avaliable for your Jeep and/or costs alot.
If you have an aftermarket radio head unit, it may have an auxilary input (like a 1/8" phone jack). If this is the case, you could simply buy a 1/8" x 1/8" audio cable to directly link between the iPod's headphone output and the radio head unit's input.
Or if you want to upgrade your radio head unit you could get a new one with an Aux. input and accomplish two things at once.
-Nick

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1988 Jeep Cherokee w/ 410,000+ miles. Now a
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