Tomica has released a good number of variations of the S2000 in 1:59 scale.  They come in two wheel variations.  Headlights are chromed and taillights are painted.  Some variations have nicely printed "H" logos on the front and rear - these have the wider wheels with the chrome (or gold lips).

A chrome silver version from a lottery box.

A silver version with the Tomica logo decal on the doors from a lottery box.

The white and white S2000s above were available only as part of these sets respectively.

Some closeups.

This is a variation from a Mall chain in Japan.

This is the Gran Tourismo version - not sure if it came packaged with the game or if they were available separately.

Another special edition version that came from a joint issue with a Takara ChoroQ S2000:

Limited Edition versions of the S2000 came in a gift set with the S800.  This version - in both pearl green and pearl red have rubber tires and more detail than the average Tomica S2000.

Some details

The outer box of the gift set.

A keychain version - note that the wheel lip is chrome instead of the gold lip on the other red one.

30th Anniversary versions - these came with special 30th anniversary boxes.

The more regular version with less taillight detail, no S2000 badge on the fender and the skinnier 4 spoke wheels.

The first Tomica S2000 had a body colored dash.

Subsequent versions had a more accurate black plastic dash.

A comparison of the two variations

Here's a "U-POHS" decorated version with its own custom box

The 2001 Tokyo Motor Show commemorative edition with special box.

The 2003 Osaka Motor Show commemorative edition S2000 with gold lip rims

Compare the fenders on the detailed vs the regular versions:

Here's the "Desktop Resort" diorama.

Comparison between the detailed version of the Tomica S2000 (red interior) with the Maisto S2000 (black interior).

Another custom edition:
 

A Toys R Us custom edition keychain

Tomica's Disney series featured a number of S2000s.

A Mickey version in a special cardboard diorama box with a Mickey figure.

A Mickey and Minnie version in white/pink.

Stitch in powder blue and red.

A commemorative edition co-boxed with a white S800

A Tomica factory specially boxed champagne colored S2000 that came with some candy. The outer box is metal containing 3 candy pouches and a white/blue boxed S2000