I was looking for a small amp to add to my car, I found a couple used Alpine amps on ebay like this:
http://cgi.ebay.com/ws/eBayISA...96769
and this:
http://cgi.ebay.com/ebaymotors...70393

are there any other amps which are half-size like those which I could buy new? those I saw on ebay look like they have a couple years on them already

 

Although they are older Alpine amps, if they are in working order and in good shape, and you can get them for under $40US then it's a good deal, however, paying for something before you know if it works or not, is not a good deal, if you can get the second one for under $10US it may be worth taking the chance.....
30W rms x 2 into 4 ohms at 0.8%THD
40W rms x 2 into 2 ohms at 0.8%THD
80W rms x 1 into 4 ohms at 0.8%THD
F/R 10Hz to 50kHz
sig/noise ratio 105 dbA
input sen. 100mV to 2V
Pretty good specs. for an amp, realy good if you can get it for under $10US 94