Funny problems get funny solutions
I have used hand held steam cleaner (about 1L of water). Part of the smell might be bacteria shit growing in the other shit, that is something that needs to be killed. The steam cleaner on the carpet etc will do that. Steam cleaner professionals do cars, as do some car detailers. Deoderisers may only mask the odour. See how you go when the deoderiser perfume wears off. There is carpet cleaner foam in a can you can buy, you brush it in.
If you need new carpet, I remember a place at Dandy that does new carpet, full interior, for any make/model.
