Having had a wrapped Mini, DON'T go down into the gutter; it is just a water trap, and don't run a knife blade around to trim the vinyl...

 

The secret to the trim is to do what is says on the instructions - put it in a bucket of scalding hot water for a few minutes to soften it, then with an assistant pull it out straight to unkink & untangle it.  Keep it pulled reasonably taught between you until it starts to cool down enough to harden up again.  As you fit it to the car, use a hairdryer to locally soften it for the corners.

+1 to what Willie said. 

Fix the rust at the drains and what looks like peeing paint above one of the drains. 

I bought similar trim at a local all British car show many years ago. Could not get it to straighten out even with gentle application of a heat gun. I still have it about 20 years later... somewhere.

I would not run the wrap into the drip channel. Looking at the photos that surface does not look smooth enough to insure a good seal. If water got under the wrap and rust started you would not know you had a problem till you had a BAD problem. I would just paint the channel to match the roof after the wrap.

going to wrap the roof white, and wanted to hear any suggestions before begining.

 

I will have the black trim coming from minimania next week. 

 

Photos here

https://photos.app.goo.gl/sXrYp8ytb9VRaMGe9

 

I'm wanting to know if I should try to get the vinyl down into the drip channel, or cut it just above.

 

The black trim will be used.

https://www.minimania.com/part/MT633-P/Classic-Mini-Roof-Gutter-Moulding-Trim-Plastic

 

thoughts, suggestions?