Based on the clue you provided, those dsp are cheap and smaller. Hmm... have not used one that doesn't allow user to fine tune. I supposed the most common unit, with a lot of sales is good enough.

pro and con.

your dsp not putting under passenger seat?
because i can fix underseat woofer+dsp (kinda huuge one) under passenger seat, and it just ngam ngam full

why fix something not broken. (no offense)

Mine was broken. The car washer I think pulled the car seat back too harsh and perhaps that day the cables got caught or somehow, damaged my dsp (which is under the seat). I saw a Chinese tiktok. Now they use a smaller dsp and conceal it underneath/behind the charging port. Remove glove compartment, then remove a small triangle like plastic cover near the charging area, and they stuff the unit in there. The cables from this dsp is also much shorter.

i suggest just buy the same model replace it if cable didnt damage.
because some time dsp have different port pin, cant interchange to use.

me installing current dsp also accessories shop suggest i put on glove compartment, but the dsp they suggest cant fit loool.

if your cable damaged, then i suggest you research and study a bit on shopee. (cant suggest much)

Can I know what brand and model are you using? I am considering a dsp with subwoofer now. Thanks in advance.

carrozeria pro-3500a
but i bet prolly a clone, and app not working, unable to tune on the fly. not suggest to buy.

for cost reference

the sembelih vibe is strong there.

Normally 2nd car service is 6 months from registration date or 1st service? I always thought it should count from last service, but the service center told me is count from registration date.
In my case, my car was registered on 29th Nov, but I only collected my car on 13 Dec, and my 1st 1000km service was done on 17 Jan. Still my 2nd service is scheduled for 29th May, which I think it's a bit too early.