CITROEN 2 CV4 1975 Owner's Manual page 29

MAINTENANCE
Maintenance
Interior
Cleaning the Upholstery
(A sample of cloth can be found stapled under the driver's
seat)
Only use mild non-caustic soaps, toilet type.
According to model:
Cloth upholstery:
This should be brushed or, preferably suction cleaned. If the
upholstery is generally very dirty, use commercial "dry foam", after
carefully removing all traces of dust.
Plastic Trim (and folding canvas hood):
This can be cleaned with a product like "SPIC" or with a little soapy
water, followed by a good rinse and wipe with a dry cloth. We do
not advise the use of products intended to make these parts shine.
Isolated Spots on Upholstery
Spots on cloth or plastic trim upholstery can be cleaned off with
water containing soap or a detergent like Teepol.
If this treatment is unsuccessful, try 90° alcohol (commercial
methylated spirit) or lead-free petrol.
Use pads well wrung-out and rub lightly.
Solvents like acetone or trichlorethylene are not recommended.