The only way in other than replacing the head unit would be the connector on the back for an external CD player. You should be able to buy an adapter that will plug in there. So long as you can get your hand up through the bottom and feel the back of the radio you should be able to plug it in. Hopefully someone knows where you can buy the adapter and will post a link.

 

there really know way to plug in the adapter without removing the radio and the cigarete lighter isnt that hard to remove just unplug the conectors then unclip the back plate then slidout the main metal round housing then remove the light holder and finally pop out the face place, the way i learned is i went to a junk yard and removed one and then put it back together so i wouldnt brake mine

and heres how you make a plug that gives you aux input

http://f1.grp.yahoofs.com/v1/MBIcR1...E1K0t6Kj1rQAsBABXKqyglXm_VkrULHUJrnGVYWvCMV86n-OgZRxKr6FfmTg2pJkeU/Previaav.pdf

 

I was curious to see how this worked but your link doesn't work bro.

 

heres another link but if all else fail go to the yahoo previa seciton and sign up and go to the files section and all will be there

http://autos.groups.yahoo.com/group/previa/files/

http://f1.grp.yahoofs.com/v1/gKYoR6...RPUOUP0KhLuqx05XtzRfmZt6v5M_8dFcQ8om5xzOIbSVzIG9qY4NQlj9SV38X7fxbY/Previaav.pdf

 

Thanks...it worked.