I would like to see a refined version of the Tamiya 414M2, Xray T1, HPI Pro 2 layouts.
I still believe that with saddle packs, these cars were the best balanced of any of the touring car layouts. Some minor adjustments for brushless motors (most likely motor offset) would make them perfectly balanced. Some new transmission gear ratios, gear diffs, new suspension geometry, Suspension mounts like the SpecR R1 and maybe a little narrowing of the chassis and I bet they would be competitive.