If the leak appears to be significant, I would not drive from FL to OH with it until it was fixed.
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If they already have not been ruined, the leak could ruin the brake pads - and the parking brake shoes (or whatever) could be ruined. Not sure if the VX uses the small shoe/drum setup for the parking brake - if so, these setups are (typically) a pain to work on and the parts are relatively expensive.
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It has been years since I replaced a rear axle seal - on some cars, you can merely unbolt the rear axle and slide the axle out so the seal can be replaced. On some other cars, the rear 'pumpkin' cover must be removed and a clip/retainer is then removed to facilitate the removal of the rear axle.
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Will - should - it be covered under warranty ? Good question.
It may be. But I would not be surprised if it was not covered.