Mouser is a great source for finding connectors. Nissan uses TE Connectivity 025 Series. You can use Mouser's connector search tool to find just about anything. Sometimes they'll be out of stock of one thing, but with a little poking around you can often find a compatible variant that is in stock (i.e. maybe a different pin clamping mechanism, but essentially the same connector).
Here is what I found:
Wire-to-Wire “male” tab housing
TE Connectivity 1473796-1
http://www.mouser.com/Search/ProductDetail.aspx?R=1473796-1
Wire-to-Wire “female” plug housing
TE Connectivity 1318386-1
http://www.mouser.com/Search/ProductDetail.aspx?R=1318386-1
Terminal “Male” Tabs
TE Connectivity / AMP 1376109-1 (Cut Strip)
http://www.mouser.com/Search/ProductDetail.aspx?R=1376109-1
Terminal “Female” Sockets
TE Connectivity / AMP 1123343-1
http://www.mouser.com/Search/ProductDetail.aspx?R=1123343-1
You'll need a terminal crimper that can handle the tiny tabs and sockets. I use an Engineer PAD-11 that does a job that looks factory and more importantly is secure and reliable. Along with some quality automotive Wire (stranded 24 or 26 ga), wire harness wrap, etc. This manual tool is a simple joy to use - my first test crimp was perfect:
https://www.amazon.com/Engineer-PAD-11-Precision-Crimping-Interchangeable/dp/B00IWD9XT6
If you screw up and insert the wrong tab/socket into the wrong hole, you need a removal tool. I didn't order one, but instead used a flat scroll saw blade I had on hand that fit the removal slots perfectly.
With all that I made my own VSP inline cable that brings out the on/off toggle line, ground, and LED indicator. I was also able to source the OEM VSP switch and mating TE connector for that. Switch is the same as the traction control button, but just a different graphic and a non-keyed plug. I finally found it on the parts diagram for a RHD car as shown on a number of third party Nissan parts sites: 251723NF0A.
For the connector that plugs into the VSP switch, I've ordered a non-keyed 025 8POS (two rows of 4):
TE Connectivity 1717103-1
http://www.mouser.com/Search/ProductDetail.aspx?R=1717103-1
(haven't yet tried to to see if it fits, but caliper measurements match stated dimensions)
BTW - the mating wire-to-wire connector should one desire to pull panel dimming backlight from a neighboring switch appears to be:
TE Connectivity 1473793-1
http://www.mouser.com/Search/ProductDetail.aspx?R=1473793-1
I believe all the other switches use variations of this connector with keys so they can't be mixed up, which may not be in stock at Mouser.
It's super helpful to have the LEAF wiring diagrams. You can buy a one-day pass and download the service manual PDFs directly from Nissan:
https://www.nissan-techinfo.com