A team from Veolia Environmental Services and fundraisers from Thames Hospicecare will be cleaning cars all over the weekend from 10am to 4pm both days.
Any donations are suggested after the deep clean, which will see cash go towards the hospice's work in Hatch Lane.
The last car wash in September at the recycling site raised £850 for the hospice's work caring for adults with cancer and other life-limiting illnesses.
Visit www.thameshospicecare.org.uk for more details.
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