I am currently doing a DIY wheel repair on a set of BMW style 189 wheels that I got for the wifes 06 325xi .. Got a set from someone on Craig's list for very, very cheap.. They were curbed up pretty badly... I got the tires removed and spoke to my body shop as a backup who agreed to take care of me if I failed in my attempt of re-painting, but I want to tackle this myself if possible..
So far after getting various grits of sand paper and sanding the taped off damaged areas with 220-600 grit paper, I can tell as long as my spray can skills are okay, these wheels that looked awful, will look good as new.. Just by sanding , filling, and re spraying the damaged area... I have all 4 sanded, got rid of about 95% of the marks and the few deeper gashes will get filler, making sure you clean between all steps is key, afterwards I will spray them with a fill type primer very lightly, than the color in only the designated area, and than clear it... Sounds hard, but I have enjoyed doing it so far and I am pretty sure the end result will be great... I went with bondo but you can get aluminum welding stuff on the internet that would be a more permanent filler if you wanted...
I'm not sure if Nissan sells a paint that exactly matches out wheels but for German cars the company Wurth, makes a color and clear that is pretty much spot on with the silver alloy wheels of BMW, Porshe, Mercedes, etc and many people over on their forums have successfully re-finished there wheels and you can not even notice..
If I fail, my body shop has agreed to take care of me at the cost of under $40 a wheel, as long as the prep work is all done. Which is what I have been doing. If I fail re spraying , I will simply have to scuff the whole wheel up with red scotch bright or 600 grit paper and bring to them to re-spray and clear.. Powder coating is a better alternative but my route I am taking... worst case scenario will end up costing me $160 + my materials ( which have been various sandpapers, a paint mixer to wrap paper in, masking tape, paint thinner ( to clean area and whip off over spray ), red bondo, and primer paint and clear... about $50 total. )
New te37s would cost you 4,000 with tires... Also a ton of powder-coaters will do it under $200 a wheel.. I was quoted 85 a wheel from a local guy to repair what I am doing and as much as 175 from another place.
here is the DIY site I have followed
Wheel Scuff Repair on Alloy Wheels | How-to Guide
If these come out good, I plan to get the paint of our wheels and tackle the few spots of curb rash on my OEM 19's ... I purchased them used having 1 wheel with some rash, and one early morning where I was half-asleep and not paying attention I curbed my rear drivers side rim on my driveway blocks. My driveway narrows down to a 1 car from a 2 car so there is a curve at the bottom. That curb mark is relatively bad and has been annoying me so hopefully the BMW wheels come out good..
Cant hurt to try this yourself!