R4s1n -
http://www.lwg3d.org/forums/showthread.php?t=14554
That should give you a good idea of how to make cars using splines. Lewis, the author of the tutorial is pretty reknowned in the Lightwave circles for his car models as you might have seen if you look in the galleries here. Its pretty much a step-by-step tutorial he's got there. The only other spline tutorial I can think of is from SplineGod but his web site seems to be down at the moment. Best of luck