The shot still doesn't say "roller coaster" to me. Again, there is no action or excitement in the shot.
I understand you were limited by the camera you were using, and having a bigger zoom would mean you could get in closer, but these two shots are just snaps of something you walked by. Granted, the something is nice, but its just a snap.
Read up online on how to compose a photograph, what to look for...things like triangles, rules of thirds, repetition, line convergance. You can still make nice photography with P&S cameras.