I don't mind if Red Bull has three cars, even with two of them looking identical. In the final race of the 2011 Sprint Cup season, Red Bull did run a Blue #4 (Kahne), Silver #83 (Vickers), and Blue #84 (Cole Whitt). The 84 did have a different sponsor (Kangaroo gas stations), but it was owned/operated/serviced by the Red Bull team.
Another option would be to put a 4th car at JGR using both year models of the Home Depot Camry, as those definitely look different. One is solid orange, and one is orange and white. It also eliminates the need to have a GameStop car. If a GameStop driver turns up, you could use the GameStop car in place of one of the two Home Depot cars. This would give two four-car teams, for a little better balance at the top of the team standings.
If we didn't go that route, we could put a third car on SGR, using two different #14s, as those look marginally different. Of all of the three options, this to me is the least appealing.
Which is more preferable at 15 cars, option A, B, or C?
Option A: 4/4/3/2/2 (more large and small teams, more like the real Sprint Cup, perfect balance 6-vs-6 chevy/toyota)
HMS: 2010 #24, 2011 #24, 2011 #48, 2011 #88
JGR: 2011 #11, 2011 #18, 2011 #20, 2010 #20 (two-similar-looking cars)
FR: 2010 #43, 2011 #43, 2011 #99
RBR: 2010 #83, 2011 #83
SGR: 2011 #14, 2011 #42
Option B: 4/3/3/3/2 (more balanced teams overall, keeps perfect 6-vs-6 balance between chevy/toyota)
HMS: 2010 #24, 2011 #24, 2011 #48, 2011 #88
JGR: 2011 #11, 2011 #18, 2011 #20,
FR: 2010 #43, 2011 #43, 2011 #99
RBR: 2010 #83, 2011 #83, 2010 #83 (two identical cars)
SGR: 2011 #14, 2011 #42
Option C: 4/3/3/2/3 (balanced teams overall, but with 7 Chevys vs 5 Toyotas)
HMS: 2010 #24, 2011 #24, 2011 #48, 2011 #88
JGR: 2011 #11, 2011 #18, 2011 #20,
FR: 2010 #43, 2011 #43, 2011 #99
RBR: 2010 #83, 2011 #83,
SGR: 2010 #14, 2011 #14, 2011 #42 (two very similar-looking cars)