* Check the part numbers: Find the part number on your existing radiator and compare it to the part number of the 1999 radiator you're considering. Identical numbers mean a very high probability of compatibility.
* Compare dimensions: Measure your existing radiator's dimensions (height, width, depth, inlet/outlet locations). Compare those to the dimensions of the 1999 radiator. Even slight differences can cause fitment issues.
* Consult a parts database: Use an online auto parts store's website (like AutoZone, Advance Auto Parts, etc.) and enter your vehicle's year, make, and model. Then look up the radiator for both a 1999 and 2000 model. Comparing the listed parts will help determine compatibility.
While the chance of it working is good due to the model's similarity, verifying compatibility using the methods above is the safest approach to avoid problems.