Mangozac said:
Silver Gray has a nice dark primer coat so the it would take a colour change fairly well.
I ment more as contrast what you see when opening the bonnet.
So what colours the strut towers are etc.
If you have titansilver, its titansilver.
But if you have sterling grey, you have antracite.
Same goes of the darker blue colours (all antracite)
And I suspect that sepang also antracite has
But I think that z4m is stratusgrey? (hard to see in the picture but it looks darker than titansilber) Is the primer colour then stratusgrey or antracite?
So this silvergrey z4 has a white/siver basecoat (I think this is titansilver, code 354):
But this looks lighter than what the OP has
And this one has antracite:
From this car (either code A08 or 440 if I guestimate, probably A08):
https://uploads.carandclassic.co.uk/uploads/cars/bmw/11184937.jpg
But sepang is a really nice colour.
I wouldnt worry about resell value.
With a respray all stonechips etc are gone so if a different colour is a negative, all stonechips gone is a positive.
I think a good respray has the best colourdepth, and I think paint has a longer lifespan than a wrap or removable respray.
But its also the most expensive. Do you know a sepang /m for sale in good condition (and can that match the shine and paint condition of a resprayed car?)