I did soundproofing for my whole car including roof. also did up the exterior wheel arch with the 3M undercoat spray as mentioned by bro Vortex. but I bought $16 per can. think i kenna chopped???

as to quiet or not, can't differentiate coz i did up all not long after collecting car. so far just feel much better than my previous ride which runs on 17" low profile tyres. it was like a lorry back then

feel that latio soundproofing is good compared to other cars like Vios, mazda2/3 etc.
most noise of latio come from tyres. engine is too quiet. so soundproofing wheel arch and floorpan is more effective. 1 thing i realised is that latio windows/windscreen not effective in reducing noise. so when big lorries or motorbikes passby, can be quite loud. but can't do anything to soundproof windows