If you don't have property insurance, then you are responsible for replacing any items in the car on your own. If you do have home insurance, you end up making two claims - one on your auto policy for the loss of the car and one on your property policy for all your personal items. Since this counts as two claims, you might want to evaluate the cost of your belongings to see if they are worth the risk of having an extra claim on your record.
If you have both your car and your home insured with us, we will only make you pay one of the deductibles. If one of your policies has a higher deductible than the other, you'll have to pay the higher one.