I need to add a hijacking run to my game. A corporate truck (with security attachment) needs to get hit by the PCs. But I can not come up with something interesting.
Anyone want to help me out?

What exactly do u want?
Advice for storming the truck or for defending it?

Watch the first 20 minutes of "Heat".

All kidding aside, there's a number of things the players need to figure out to be successful.

1) What is the truck's origin?
2) What is it's path?
3) What is it's destination?

I presume if you figure out ways for them to find that information, they will come up with a scheme suitable for hijacking it. Also, don't forget if it's important enough to have a security detail, it's important enough to have a helicopter available via backup!

-DrZ

Have the truck breakdown at a location short of the ambush spot so that when it doesn't show, the group panics.

The truck is just a decoy. The actual merchandise was sent in the back of three separate unmarked taxi's.

Someone else is trying to hit the truck at the same time or before the PC's do.

The cargo is a shipment of Nosferatu that have been captured and are being transported for study. When they open it up they're going to be in for a surprise. (the securities there to protect everyone else, not to keep people from getting to the cargo)

They truck has aerial overwatch, so the only point to hit it is while is going through a long tunnel.

Traffic jam.

The whole inside of the truck has been coated with contact poison, so that unauthorized removal results in a serious harm or death.

Awakened critters, plants, etc. For example, haven lilies in the truck.

It's a trap. They manage to grab the goods easy enough, but everything had tracking nanites that get absorbed into them so they can be found. Now the question is, was it a trap for them, or just someone who can pull a job like this off? Is it personal? or is there a job on offer?