For the love of god how do I do a vehicle maintenance script?

I've searched long and hard, followed many instructions, but it just DOESN'T WORK. can someone please help me with this before I explode? Thanks!

some info would be nice, maybe the script your trying..?

Or have a look at this thread:

http://forums.bistudio.com/showpost.php?p=1364481&postcount=5

Easy to adapt it to your needs.