Few things to look out for....
Their are very few aftermarket parts for them.
Rust in the floor between double skin behind middle row of seats
Steering is very weak in the grand scheme of things....do a 2wd navara steering mod
The 98 SLE blacktop intercooled TD27E.t.I engine is quite powerful..in standard form actually produces more then a td42-t however the downside to this is the electronically controlled pump with it's timing advance and fly by wire needle lift control makes for quite a complicated system that is not with out issues. Mainly the wear on the magnetic lift valve which can get costly. Easiest fix is swap in a qd32 injector mechanical pump.
They also have a Garrett turbo charger which is very good an capable of 18-25 psi compared to the earlier mistral.
Front suspension is another Achilles heal.
Very poor setup from factory compared to
other I.f.s trucks but can be made strong.
Lastly if when on inspection the transmission fluid is neither clear or red(depending on brand of trans fluid) walk away. Apart from that they are otherwise pretty good little wagons with factory h233b rear LSD, can fit LSD to the front, room.for twin batteries, can fit 32's with out too much issue and disconnect on the sway bars will have it walking through most obstacles when crossed up.
it will be summer soon...