just my 2c worth. my expierience with printing stickers is that....
Mansoor your first idea where you say its a clear sticker, remeber if that sticker is printed on a clear surface your ink/design is going to be translucent so if you stick it to your window you wont quite see it, unless you stick it to the body of your car. a better option would be to have it vinyl cut as you only have 2 colours, the grey and blue. but then you would have to make the blue outline of Sealine solid like in the black design.
you could have the glowing effect on the black design coz you would be using a black backing to print the sticker on.
@Reefman: your designs are not vinyl cut friendly because of all the colours. and i think it will work out more to print your designs because of all the ink being used.for all ur designs you will need to use a white backing as you cannot print the colour white and then have to fill the sticker up with all the different colours/shades etc..
i will take some fotos of stickers i designed for my own use and post it tomorrow....