So I have a 2000 TL Base and want to know if I can mount a 2002 TL Type S front bumper cover to it?
Or will I just have to find an aftermarket front bumper cover?

 

The answer is no for 2003 tls bumper and yes to having to buy a front bumper cover. Ebay had a primed one for around a hundred bucks. You might get lucky at a salvage yard but very unlikely to find one that matches the color of your car. You might have to sand and repaint it also.

 

I don't think that will work. The bumper may line up and go on, but the grille won't, and there will be a little gap under the headlights, as the 02-03 ones have a circular notch for the headlights, whereas the 99-01 do not.

 

Yeah, as these guys said. Try to locate a used '99>'01 front bumper cover if ya want it to look right.

 

You will need the Hood, Fenders, Headlights, and a bunch of misc parts from a 02-03 to make that bumper fit

 

Yeah, it can be done.......but, as Fsttyms1 detailed the extra expense in additional parts and effort required just are not worth the bother !!!