Are there any extra measures when designing a translucent business card?

My client needs a translucent business and this is the first time I am going to do create a design that's going to be printed on translucent plastic material.

I am a bit worried about how the design will work with it. Are the transparency going to work just by leaving transparent background in the required areas and setting opacity value of layers to something more transculent.

Here's an example of the stuff I am talking about

My question is should I keep working the way I do for paper business cards or there are some extra steps to take to achieve a perfect translucent effect. And do I also need to change the documents property from CMYK to something else because I guess CMYK doesn't produce PNG outputs.