One thing to know is that while the Nissan wheels will fit the wheel studs, the hub center is larger than the MR2 hub spigot that is 60.1 mm. If the wheel is fitted like this you may have trouble balancing the wheels.
Concentric hub rings are usually used to fix this with many aftermarket wheels, however
you wont find off the shelf hub rings to fit to adapt Nissan wheels to the MR2 hub.
Some people get metal hub rings custom made to fit, however another option would be to buy cheap aluminum rings with the right MR2 center and get the center of the wheel machined to take them as shown in the pics.