Come on, think. A four seat airplane about the weight of a Volkswagen isn't a 400 thousand lb 767 just because both of them have wings.
And that's coming from someone who doesn't realize it would be much easier for a lone terrorist to fly a small plane into a building than to obtain 20 ton truck collect enough barrels of fuel to fill the truck with enough power to bring down a 50 story building! Terrorists want spectacular events. Today's crash proves a even a small plane flown by one person can be spectacular and create as much devastation as any one terrorist could create.
Keep thinking.
Really? How many terrorist pilots are there? How many terrorist drivers are there?
The truck place is called "U-Haul", and they don't even require the two hour check-ride to rent.