For those who have asked for some help in choosing good base color/texture matches, I've compiled a partial list which may save you some time. The only way to find out what really works is through trial and error, and that's how I've arrived at all of these matches.

Let's look at pavement first. Of the five enhanced tracks, asphalt textures from all except Elkhart Lake are usable (its hue is rather unique). Here are the tracks for which I've found the four remaining enhanced asphalt textures most appropriate:

• LAGUNA SECA: Detroit, Long Beach, Loudon, Mid-Ohio, Pocono, Toronto, Watkins Glen
• MICHIGAN: Darlington, North Wilkesboro, Richmond
• PHOENIX: Australia, Indianapolis
• PORTLAND: Atlanta, Nazareth, Vancouver

None of the ICR2-3D enhanced asphalt textures works well for Charlotte, Dover, Rockingham, or Sears Point (whose base colors are too dark), with Bristol or Cleveland (base colors too light), or with Martinsville (both); Milwaukee is also problematic, with its unique base color. But with N2 asphalt textures readily usable, matches for darker or lighter base colors are available. As mentioned in the basic texture swapping information section, I found that the N2 Talladega provides great asphalt for Cleveland, as does N2's Sears Point for the N1-converted Sears Point. (As I recall, the names for the pavement textures in the N2 Talladega are deceptive: the CONCRETE texture is actually darker than the ASPHALT.) There are probably reasonable matches for these tracks among the N2 textures.

Close base color/texture matches are also important in grass enhancement, though there's usually a bit more leeway (depending on the track; the grass base rolls out more noticeably at some than others). Take a look at the base color of the grass you'e replacing, and base your choice on the following:

• ELKHART LAKE: dark green, natural; doesn't lend itself well to other tracks
• MICHIGAN: deep green, manicured
• PHOENIX: bright medium green; artificial look
• PORTLAND: lighter green, very natural

I chose not to replace the grass at some of the tracks, finding the original textures satisfactory - for example, at the N1-converted Watkins Glen.

Among the other texture enhancements which depend on base color/texture matching are Armco (use Portland's if grey, Laguna Seca's if red) and walls (use Michigan's INWALL if white base color - e.g., Indy - and the wall from Elkhart Lake, Laguna Seca, or Portland if tan - e.g., Nazareth). Of course, walls with adverts will probably not match the new texture perfectly, unless those too are replaced with new files, but you don't tend to notice that in the heat of competition!

Sky and horizon are another major area of enhancement, and you're limited to combinations of sky and horizon which match. One thing I've found is that Michigan's sky blends extremely well with existing horizons like Australia's, Cleveland's, and Nazareth's (which aren't easily replaced). For those horizons which are rather nondescript, one of those from the enhanced tracks may be used as a replacement; it will probably not be too authentic, but you'll have a sky texture which blends well (and anyway, how often do you really look at the horizon while you're racing?). For instance, Nazareth's horizon files and Michigan's sky files make a reasonable backdrop for various tracks. And since Australia's horizon and Michigan's sky blend well, you can get away with using those files at the other street courses without noticing too much of a difference in the horizon.

Probably the best crowd M16 is Michigan's. If you want to enhance some trees, check out Portland's and Elkhart Lake's. And don't forget that 76 ball (65.MI4) from Michigan (see basic texture swapping information). There are all sorts of objects and textures that can be swapped, so long as they're appropriately renamed and the new extension noted in the PCK file if it differs from the original. And as far as enhancements that don't depend on blending with a base color, such as crowds and trees, it's solely a matter of personal taste.