I got an almost 5 year old Weimeraner that has no problem taking rides in the truck. This is his (my) 3rd Nissan truck. He has taken summer and winter trips 3 times (2,700 miles round trip each time) once in an 02 Xterra and twice in the Titan. He has gone in my old 02 Frontier to a truck meet in Tampa which is the other side of the state for me. He rides almost everywhere we go, as long as I don't have to leave him in the truck during hot weather.
Heres a couple of pics that best show his association with trucks.
http://www.picturetrail.com/gallery/...734&uid=609633