i want to buy this stereo receiver today ! but have some questions

Asus_

If you want single din, the kmm bt322u is ok nothing amazing... but if you spend a little more you can get probably the best single din head units made for sound quality, period... they sound amazing are powerful and bring your music to life.. "a receiver that's built for SQ from the ground up"

Pioneer DEH-80PRS (more affordable version then the P99RS)
https://www.crutchfield.ca/S-DSjuMFw...DEH-80PRS.html

Pioneer DEX-P99RS (pricey but the best for sq u can get)
https://www.crutchfield.com/S-uMxU7E...DEX-P99RS.html

These 2 headunits are the go to if you really want sound quality, they were made ground up specifically for this reason. Although there is allot of tuning that will go into these headunits because they have a built in DPS (Digital signal processor) but once you have your settings adjusted and tuned, it will sound better then anything else you can buy.

You will have to shop around online as some places they will be expensive but i have seen some very good prices from a few other sites

1 left here.. but u can find more.
https://www.amazon.com/Pioneer-DEH-8...70_&dpSrc=srch