My usual response to this kind of question is that you shouldnt worry about it, and let your publishers lawyers handle it. But you state you are self publishing, so here we go:
When a car manufacturer sells a car they can no longer control what the purchaser does with it. If they use it to commit a crime, that does not in any way reflect on the manufacturer. Therefore, suggesting that this may happen does not damage the reputation of the manufacturer, so they have no legitimate cause for illegal action.
Things may be different if your story suggests that the model of car was specifically more useful for this purpose than others and the manufacturer knew or should have known this, or if they were aware it would be used like this and did nothing to prevent it.
Of course there is nothing to prevent a company launching a baseless legal suit against you, but this seems unlikely. At least where I live you can get insurance against legal costs relatively cheaply, which is something it may be worth investing in. I would suggest this for all small business owners, and self publishing is no different.
(I'm not a lawyer, but have researched this subject to be confident that this is what most lawyers would say about it - but obviously this is not legal advice and you should probably confirm this with a specialist in your jurisdiction)