What happens if I am in an auto accident and the other party does not have insurance-I don't have collision insurance on my auto insurance?

If you had no collision coverage at the time of the collision, you cannot get it after the fact in order for the insurer to pay for repairs.

If the at-fault driver had no liability insurance, your only remedy would be to sue him/her for the cost of repair and whatever other out of pocket expenses you incurred; these may include the reasonable cost of renting a vehicle while yours was being repaired.

If your vehicle was totalled, your lawsuit against the at-fault party would be for the actual cash value of your vehicle as of the time of the collision, plus other out of pocket expenses that you may have incurred as discussed above.

In all events, it will be your burden to prove negligence on the part of the other party in order to prevail. Additionally, you will need to prove the nature and extent of your damages by means of an "expert witness", such as the auto body facility's representative who examined and wrote the estimate for repairs. It is not sufficient merely to present the written estimate, as the opposing party must be given the right to challenge its validity by cross-examining the person who prepared it.