no
NO.
5w30
6.5''
...really? Without sparkplugs the engine will not be able to start up and run...so to answer your question yes the 2005 Dodge Dakota has sparkplugs.
Unfortunately, there's no available auxiliary input.
NO.
No, the offset is different.
The flasher in a Dodge Dakota should be located in the fuse box. The box is under the drivers side of the dash.
NoNo
It is on the bottom of the trans.
It wasn't built with any.