I believe the minimum dimensions for 1-car garages in the United States is 10'x20'. This is plenty of space for a Camaro. I know because I keep my Camaro in a 10x20 garage. There is enough room to open both doors to the first detent and I still have about 4 feet of room in the front/rear (depending on how far I park the car in the garage).
2011 Summit White Camaro 1SS/RS
-6.2 LS3, TR6060, 3.45, G80
2004 Black Silverado 1500 2WD Regular Cab, Short Bed
-5.3 LM7, 4L60E, 3.42, G80