Recently looked at some 2012 Camrys at a local Toyota dealer and was somewhat shocked to see that none of the power plants had an exhaust manifold shield/cover. While the average Joe/Jane probably wouldn't notice anything amiss, this was the first thing I noticed after popping the hood.
The salesman claimed that they rattled over time so Toyota had stopped using them. A head mechanic said that they did have covers originally but the upstream O2 sensors had to be replaced with longer ones and so the covers could no longer fit.
Here is a picture of the 2012 Camry power plant showing the unsightly area;
Here is a picture of a 1996 Camry power plant;