Can you simply remove seat covers and put them through a washing machine? Can vinyl be recoloured easily? Well, in theory, putting the covers through a ‘delicates’ cycle in the washing machine should bring them up a treat.
However, you should first consider how difficult it might be to remove the covers and refit them. Also, the machine will quickly find any weaknesses in the aged fabric and this may result in unexpected damage.
If you’re not confident, there are many products aimed at both domestic and automotive fabric cleaning that can be used in situ.
Once you’ve gently cleaned the seats, you could well achieve good results with a vinyl-recolouring kits. And it could be a lot less stressful than removing the covers!