No. Cargo insurance is commodity specific and if you read your policy it likely excludes automobiles, light trucks and similar items. Most brokers will not load you, at least the reputable ones, if you do not have the proper cargo insurance. Even if you can get loaded, have a claim and it will be denied and you will be buying a car out of your own money. This is especially important for new cars where a small, seemingly insignificant ding or scratch can total a car or reduce its value enough that the carrier has to buy it for full retail price. These losses are diminished value and constructive total loss, look into them.
Also, your public liability (MCS-90) needs to be a minimum of $1 million to meet the FMCSA requirements to be an automobile transporter. Most general freight haulers only have the minimum of $750,000. So, when you update your MCS-150 (US DOT number) to show automobiles or driveaway/towaway as types of commodities hauled you will also have to make sure your insurance is up to the $1M minimum.
Thanks for the info. I went ahead with $1 million for general liability and $100k in cargo, so I'll call progressive to add autos if I do decide to haul vehicles. Do you know what additional insurance I would need to haul travel trailers or enclosed trailers?