If he took the breath test, then his license can be suspended for 6 months by the DMV. If he refused, it is one year by the DMV. That is for the first time. If he is found guilty at trial or pleas to a first time DUI, the maximum penalties are one year probation, $1000.00 fine, court costs, 50 hours community service, DUI school, Victims Awareness Program, and 6 months DL suspension, and adjudication of guilt. The fine is the maximum, as well as the probation, everything else is the least that can happen.
He can get a business purposes license after 30 days for a 6 month suspension and 90 days for a one year suspension.
It sounds to me like you are asking whether you have any responsibility for his crime. If so, the answer is no. You didn't drive under the influence, and so you don't have to worry about criminal culpability. However, you should be concerned that you might be legally liable for anyone that he injures while driving your car. Florida is one of a minority of states that considers an automobile a "dangerous instrumentality." This means that any damage that is caused by someone driving your car is chargeable to you and to your insurance. If he were to go out and injure someone while driving your car, the lawsuit would list you and any other registered owner of the car as a defendant.
But you can't be punished criminally for his DUI in your car. Good luck.
When interviewing a DUI defense lawyer ask the following questions:
What percentage of your annual caseload is relegated to defending DUI?
How many DUI jury trials did you have in the past 12 months?
Can you provide a list of DUI training seminars or conferences attended in the past 2 to 5 years?
What percentage of your clients enter a plea of guilty to the crime charged?
Have you or any members of your firm written articles or books related to defending DUIs?
How many lawyers are in the firm, and are they all DUI defense attorneys? If so, will they collaborate with their colleagues about your DUI case?
How many years have you defended DUI cases?