I am really surprised that you can't give us any source, let alone context, according to you. 'Context' includes why you are writing and composing these sentences. Now, items like remains/ left-overs/remnants/ the rest of ..., can be tricky for learners, especially as there are 'false-friend' words in other European languages. When people ask about these words they usually come up with an everyday example sentence such as

" Nobody liked the food so we had many
rests to throw away"

. It is very unusual to ask how to describe what's left of eleven Egyptian chariots! Perhaps you are trying too hard not to copy your source word for word.
One of my major leisure interests is archaeology. I wanted to be an archaeologist and I participated in digs in my youth. I watch and read everything I can find about it. I have no problem at all with 'remains' being used for objects or inanimate anything at all - villages, villas, Iron Age hill forts, temples, mosaic floors, causeways - as well as skeletal remains. There are other words that might be used for certain types of material or substances, words like remnants for fabrics or traces for foods but remains of chariots is fine. It includes quite damaged items or fragmentary items and well preserved items such as the chariots in pyramid tombs which might be intact.
Hermione