Right, I've completed it on easy but I'm stuck on Normal, I need to do..

I'm thinking that Barcelona is the level before Berlin, so I'll just say where those SPAT signs are...

One is over by the Arcade Machine.

What you need to do is get on the roof on top of the Arcade Machine. This is how you get to the roof: when you go over to the place where the Arcade Machine is at, you should see 3 yellow rails.

Grind those 3 rails toward the wall (away from the "ocean") and when you ollie off of the last rail, you should run into a medium-sized billboard.

Quickly Sticker Slap (press A) that medium-sized billboard.

Now you should be on that roof (get off of your board so you won't fall) and on the wall there should be a SPAT sign.

The second SPAT sign is over at the big place on the edge of the level that I think starts with a G. The place contains the "World's Longest Bench". Go up to that place and face it.

Now, go to the right and you should see some QuarterPipes. To the right of the QP's is the second SPAT sign on a brick fence.

Remember the goal where you have to find the 3 Flips? The third sign is at the place where you had to find the Mambo Flip or something like that.

Sorry if the name is different but I know it starts with an M. Go to the middle of that place and the SPAT sign should be somewhere on the wall of the white and red building.

Do you know that place with the big long Spiral Rail? Go to the very bottom of that rail and go right outside.

Now go to one of the sides of the building and the SPAT sign should be right outside those doors on the wall.

The 5th SPAT sign I can't explain. You should go to a SPAT Sign Walkthrough on this site.