Plastic radiator? Interesting.
Some garage doing this kind of deal just as 冬said, especially for expensive like Lexus. They rebuilt the parts or sometimes too lazy to rebuild, just sell to third part for rebuilding.
pretty interesting.
Should not break again in one year. Plastic last long if not mechanical impact on it. I think you can get old radiator back, but be sure to find a crap yard to sell before take back.
APA has a list of very good and honest garages but you need to be a member to obtain this list. Phil Bailey's garage does excellent job. Nelson Garage on Decarie also does great job (nelson garage is recommended by APA as well). You can go to either one.