Kimber 4tc good enough?

Try Canare 4S11 single, not bi-wire and get a ft. or two extra and make your own jumpers. Use to own 4 and 8TC and I find it’s a little grainy and forward sounding. You’ll find the Canare is more relaxed or natural with a better stage. Canare takes a lot of hours to burn in so give it time. Can be purchased off Amazon among many places and it’s very affordable. Search here and other places to learn more. It’s a great cable and I feel walks all over the Kimber. You’ll have to spend a lot more to do better.

Never owned a Honda Civic, or ever driven one... but I’ll take your word on that.

For the bass, 8VS or PR will do just fine too. Probably just another pair of 4TC will be more than sufficient. Have you tried the cotton rope inside the weave and just use some quality jumpers and not the straps? Easy just to get a short stick of 4TC and unbraid it, take two strands and twist to make your own jumpers.