I hate to inform of the previous posters but YES ticks can be that small. They are refered to as seed ticks. We have them pretty bad around my house. More than likely no the steam won't kill them. I know that dial soap and other disinfectant soaps make them flee for their lifes. My suggestions would be go and buy some mosquito spray that has deet in it and spray your vehicle and leave the window open for it to air out. They have kinds that don't stink real bad too. The deet will kill them for sure and if not kill make them flee your vehicle. Just remember where ever you run them out at that is where they will be to catch their next host.
youre telling me that steam of a temperature of higher than 212F is not going to kill ticks?
i'll believe that some ticks might be small... but i won't believe that a temp that high wouldnt kill a tick.
oh, and DEET is not exactly a good thing to be spreading all around where a 3 year old is involved. great for use in adults and older children, but smaller children and their exploring ways can end up ingesting it.