Yes, Jaycar did once produce quality car audio components.

Jaycar Response 4" 2 way speakers - Model CS2280

These run 40W RMS.
The tweeter is directional.
They are pre-wired with a crossover.
These were a shade under $130 new and rated a competition winning 9/10 in a comparison of $150 and under 4" speakers.
They are described as "very clear and the bass was extremely firm and responsive" and "The Jaycars do not disappoint, exhibiting smooth clean response throughout the audible spectrum. Guitar and vocals sound strong and clear, imaging well. Bass and percussion is also impressive, with good tonal accuracy and excellent balance. These speakers make for an outstanding sound at a reasonable price"

These have been used, yet at a power rating way below what they've been rated for, so have not been driven near their power rating and only for a period of about 6-9 months.
These fit the factory AE86 moulds and I found them to be a great upgrade without even amplifying them.
Can only imagine what they would of sounded like with a modest Amp.
These will come with cutting template screws and everything else left in the box, inc the grilles in unused condition.
By memory, these had great Signal to Noise ration(S/N 90+db) and a very low distortion (fractions of a percent THD) rating.

Instant $110

Jaycar Response Super Tweeters - Model CS2210

These run 40W RMS.
They come with mounting hardware.
They are unused.
These got great reviews and are a great compliment to the above splits for a great overall front presence (would be even better with a 4x 50W RMS amp with the gains turned down a bit).
These sold new for $55.
By memory, these had great Signal to Noise ration(S/N 100+db) and a very low distortion (fractions of a percent THD) rating.

Instant $45

Jaycar Response Precision Amplifier 4x100W RMS - Model AA0456

A compact chassis small enough to mount under a car seat and 100WRMS from four channels. This is a very efficient full range amp designed to drive full range speakers and is able to produce 550WRMS bridged. It shares the same features as our other Response amps such as insert-type connectors, variable high and low pass filters and variable bass boost.

Specifications:
• Power / channel @ 4ohm 14.4V: 100WRMS x 4
• Power / channel @ 2ohm 14.4V: 150WRMS x 4
• Power / bridged @ 4ohm 14.4V: 300WRMS x 2
• S/N ratio: >90dB
• Input sensitivity: 200mV to 5V
• Low pass filter: 50 - 500Hz @ 12dB/octave
• High pass filter: 50 - 500Hz @ 12dB/octave
• Dimensions: 4300(L) x 170(W) x 50mm(D)mm
Possibly a Class DE with a 110db S/N ratio

Been advised that 3 channel is as below, yet not 100% sure of this...
2x130W RMS, stereo @ 4ohm
1x380W RMS, mono @ 4ohm

Apparently these are great budget (both price and space) conscious Amplifiers, yet I never got the chance to run this in anger, let alone power up.
Currently being advertised on special for $319 with a RRP of $479 (yeah, not happy Jan)
This is unused in condition. (The screws show no markings for wires to been wired in yet mounting tabs have shown it's been mounted)

Instant $300

I'm located in Sydney and able to deliver at a nominal fee.