how long does 3 miles take with a car
To be a car designer, you have to take a course in transportation design. There are many schools that offer design courses but worldwide there are only 20 that offer Transportation or Automotive design.
as long as you need and decision making
You can't drive the entire way - Ireland is an island, and they have yet to design an oceangoing car (even the DUKW could only traverse the calmest of seas for short distances).
not very long cuz your way too fat
It should not take very long to finance a car, depending on the car's model, condition, etc and also the finance company you are financing the car from.
Depending on the jeweller and the type of design and the intricacy of the design it probably could take up to a month to design a nice class ring. You would have to find a specialist in this field.
It depends on what kind of car it is
Three years
a long time
8 hours by motor way - it is a long journey by car
... from where..?