This is a free play kind of level, so I don't know which canister you're talking about. Here's the info from IGN:

In the Single Player mode:

Talk about beginning a level in style! Manning the ever-so-sleek Batmobile, race down the congested streets of Gotham and blast everything in sight. And we mean everything. You get a lot of studs and secret items this way, including the first LEGO canister from the manhole cover. A second LEGO canister can be collected by trashing three blue and white dumpsters.

Now the real underlying goal (besides the shooting frenzy that is) is to pelt the green trucks enough times so that they tip over on their side. Then attach a tow cable from the Batmobile and haul the sorry criminals to the bat signal on the ground.

The same basic principle carries on to the next area, where you will have to go and round up the green-colored trucks and turn them in to the police in the back right corner of the map. This time, however, you need to drag three of them. The area may seem rather sizable this time around, but road barricades have been set up all around to ensure you don't stray too far from the desired route. And, of course, obliterating everything in your path will net you four LEGO canisters total.

In Free Play:

With Joker's van, drive onto the Joker-painted panel near the harbor to get a specially delivered crate on the docks. Claim the LEGO canister within. Similarly, drive Harley Quinn's Hammer truck onto the corresponding Harley panel for an additional LEGO canister.
--
In the middle of the encounter, locate a shiny wall and goad Two-Face to fire a bomb near there. A proximate explosion should open the way to the last of three vendor carts needed to unveil this LEGO canister. Drive into the grassy area on the left side, near some green containers, to find an alcove leading to a red power brick. Blast the phone booth for a LEGO canister as well.

Check out the walkthrough for details.
Source(s):
http://guides.ign.com/guides/896273/page_9.html


Permalink | Report