If you are invested in satellite radio it is important that you monitor the auto sector as it is the source of most of Sirius XM's growth and where many consumers first experience satellite radio. Gauging auto sales has its challenges, but knowing what manufacturers are doing in terms of consumer incentives can give you insight into how the current month will perform.

In March GM carried fewer incentives than normal and we saw a substantial shift in the auto sector. Ford surpassed GM in sales volume for the first time in a decade, and was a huge benefactor of GM's move. In April GM has throttled up the incentive pressures again, as have several manufacturers. This could be an indication that April will deliver yet another strong month in auto sales, and that is good news for SIRI investors.

GM, Chevrolet, GMC (Includes Chevrolet, GMC, Buick, Cadillac, HUMMER, Pontiac, Saturn, Saab) - Up to $5,000 cash back and 0% financing on many 2010 models. Up to $3,000 on some 2011 models.

BMW - 0.9% to 3.9% financing for up to 36 months. Up to $3,500 cash back on some models (even some 2011 models). Hidden dealer incentives of up to $12,500.

Chrysler, Dodge - Cash rebates up to $5,250 on some models. 0% financing up to 72 months. Hidden dealer incentives of up to $1,000.

Ford (Includes Ford, Lincoln, Mercury) - 0% financing on most models. Rebates as high as $5,000 on some 2010 models.

Honda - 0.9% to 2.9% financing on some models. Hidden dealer incentives of up to $2,500 on some 2010 models

Toyota - 0% to 3.9% financing on most models, rebates as high as $2,000 depending on region. Hidden dealer incentives up to $4,000 on some models.

Nissan (Includes Infiniti) - 0 - 4.9% financing on some 2010 models. Up to $5,000 rebates on some models.

Hyundai (Includes Kia)
- Up to $2,500 cash rebate on some 2010 models. 0.9% - 4.9% financing on 2010 models.

Mercedes Benz - 1.9% financing for up to 36 months on some models.