tbh their work look good, however, how much did they charge for work like that, im guessing big £££
car audio is very easy to work with, just disconnect the +ve terminal on the baterry before you do anything
label all wires with their correct terminals, as they have already been correctly fitted, make your amp rack, re-fit the amp, install the wiring as previous, refit battery terminal
a job done, 1 hours work, and great satisfaction
if you lived locally i would have done the job for you (corby, northants)