monsoon speaker replacement 2003 jetta a4

I have a 2003 jetta 4 door with monsoon. GL trim. I replaced the stereo head unit a few years ago and decided to replace the speakers. Since I'm using the existing wiring I bought a pair of component speakers (no names, but they had a pretty decent rating). The existing speakers were 2 ohm speakers so this is what I bought for replacement. I noticed after replacing the woofers that they weren't very loud as the existing speakers (I left the front speakers in and was planning to replace them later). I DID check the polarity on the speaker wiring before hooking them up so that isn't a problem.
I'm considering ditching the speakers I bought (they were under $30/pair). I'm not that big on having to spend $200/pair on speakers. (My hearing was a lot better in my 20s but I do remember having friends who spent $1,500 or more on a system IN 1980 DOLLARS this was a lot, and I wasn't all that impressed for the amount of money spent.)
NOW, for the question.... If I decide to replace with a coaxial speaker, the 2-way or 3-way kind, can I twist the 2 pairs of separate positive and negative wires together where they come out of the wiring harness in the door? (I've heard that you can do this on a couple of people's youtube channels, but didn't know if it'd work).
OR....
If I get another pair of component speakers (I'm considering Infinity speakers in the $85-110 price range) can I leave out the included crossover if I'm going to use the existing Monsoon wiring which is, in effect, a crossover? I really don't want to mess with install people again. I had originally bought a Pioneer headunit, double DIN which had a built in GPS that didn't work. I brought it to an install guy after I did this self install and he soldered the wiring in place (I used a harness adapter). He neglected to tell me that he wasn't able to get the GPS to work either.
Let me know what you think......

When I installed my Kenwood d-din unit I ran new wires from the radio to the 4 doors.
I wanted real speaker wire, not x-mas tree wire.

I also yanked the amp out of the back so it would not draw power or cause unknown issues. The Kenwood has 50 watts x4 so I didn't need it anyway.
Took a few sessions for this running under the carpets & such -and- connecting them to the speaker end only.

When D-day came and I installed the radio and yanked the amp then.
Ran new power wires also, did not tap into the car wires for anything.
For me it wasn't that bad a job and the radio sounds great.
It also came with a GPS antenna, did yours?