I recently bought a very nice 924S to use while my 914 is worked on this summer, A very nice car with just 47k miles and two documented owners.
Car was let down by its shabby faded floor mats, the over-mats were original to the car and even had the original documentation on 'How to keep your Porsche carpet floor mats looking their best' Not thinking there was much I could do with them I invested in a pair of Coconut mats for the driver and front passenger from cocomats.com. I bought them in red/black to compliment the cars red exterior and they really are well made mats, in fact far better than I ever imagined. I thought once my 914 was done I'd invest in a set for it.
Then by chance I stumbled on Detail Kings carpet dye kit, with nothing to much loose if I messed up the faded carpet I bought the black kit complete with their their spray bottle.
Too wet to do much today I thought I'd give it a try, I'd previously discretely washed the mats in the washing machine . simply mixing the dye with warm water and spraying it on the mats followed by working it in with a scrub brush, no odor either. The result is remarkable!. I taped the Porsche text with painters tape to save it. I think you'll agree they came out really well.
dye kit cost me $32 shipped! www.detailking.com
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After:
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My 914 has a brown interior and the carpets are the originals, I plan to dye them too.