i know this may sound stupid by i'm confused.

1.) if i already have a manifold for my turbo and i want to ask a shop to fabricate a downpipe for it, do i have to leave my car at the shop til they finished the downpipe? can i just bring the car in and let him do the measuring then take the car home and come back for the downpipe? how long can a downpipe be made?

2.) lastly, what if i don't have a manifold and downpipe yet and i ask a shop to make one, do i need to leave the car to them?

i asked these coz i don't like leaving my car to them as much as possible since i use the car everyday and public transport are a bitch from where i live.

 

Hard (near impossible) to make a downpipe (that fits) off the car... so you'd want to leave it there.

They'll need the manifold and turbo to make a downpipe. Unless they have a spare motor just like yours they'll most likely need your car.