What I'm referring to is cars with the "hidden" battery. The battery isn't in the top corner of the engine bay. It's below a fuse box or something, and room could be an issue. Is it hard to do battery swaps with larger batteries in those cars?
No that makes zero difference. Put a Crescendo BC5500 on two Zv4 12s in a 300c with rear battery. Took out the spare and added three more Stinger AGMs.