At first, choose the car that is easier to drive. Between a car and a large SUV, use the car. Between an automatic and a manual transmission, go with the automatic. Using the car that is easier to drive allows your teen to focus on practicing the skills they're learning at Swerve in the safest way possible. Driving a bigger vehicle may cause anxiety, which can slow their progress.
Having to learn how to shift the car and operate the clutch will almost certainly take attention away from developing good visual habits and other fundamentals. After your son or daughter is more comfortable with driving and has built some competency, then you can add other complications like shifting or driving large vehicles. If all you have is a large vehicle or a manual transmission, your teen can still successfully learn to drive but be sure to understand that progress will probably be slower while your teen gets accustomed to the vehicle.