Do I need to transfer tape?

[AUTO-FX]

If the air temp is right, you can do that without tape and dry. If you're squirrelly about it, I would tape it then and still do it dry. No need to do that stripe wet, or pissy, though.

 

[OneUpTenn]

No tape here....too much trouble. Lots of fluid and peel off the backing as you go..but do not even stretch it a little or you will not have straight lines.

 

[Sticky Signs]

Here's what I would do depending on the vehicle and the stripe.
I'd start by running some masking tape down the side of the vehicle. The bottom of the mask goes where the top of the stripe should go. The tape acts as a guide and it allows you to see if you're line is straight.
Now line the top edge of the stripe to the bottom of the mask and tape it down in several areas. I would probably choose to use the hinge method and most likely dry if it's a fairly flat surface. A little rapid tac never hurts though.
Good luck!