Much to the chagrin of some of the people whose rides were pimped, some customized improvements, such as front-seat LCD screens, extra-large bass speakers, etc., were only put in for the purposes of the show, and had to be removed immediately after the episode was filmed, since such customizations would run afoul of traffic laws or noise ordinances, the existing wiring in the car simply couldn't handle the additional electrical loads, or the customizations would compromise federally mandated safety equipment such as airbags and seat belts.
Many of the people whose rides were pimped were surprised to discover that the customizations to their cars were, in fact, not quite as free as the show portrayed. Because the show paid for the improvements/customizations and labor, or provided them to the participant for free, officials from both the IRS and California Revenue Tax Board (since both the show and parts provided & the work performed to the car were done in California) considered this to be income paid to the participant. Much like game show winnings, the equivalent market value of the improvements were reported as such to Federal and State authorities, with participants being stuck with tax bills amounting to several thousand dollars in some cases. This forced a handful of the participants to sell their newly pimped car off to cover the tax bill or face fines, penalties, interest, or even jail time if they failed to pay the taxes in time. Only a small number of the participants, who used their car for their small business or to travel extensively for their job, were able to side-step the issue by claiming the pimping/upgrades as a tax deduction as part of their employment.
The show now takes place at GAS (Galpin Auto Sports) Garage instead of West Coast Customs with all new mechanics, although Mad Mike still stays on the show.
Some of the cars on the show that were 'pimped up' turned out not to be the original car they started out with. The reasons were the cars were too far gone.
It later turned out that much of the subjects' stories were not as sincere as portrayed. Many were actually older than they said, the houses that Xzibit met them at were not theirs and, as one would guess, they already knew he was coming and were supposed to act surprised when they opened the door. It also turned out they made the cars look worse than they really did, and also added more trash and other things to match exactly what they were looking for. Furthermore, subjects were coached on how to react to their final reveal, and at least one person was taken aside and was as good as threatened for not showing as much enthusiasm on the reveal as they would've expected. Also, contrary to what was said, the pimping process took 6-8 months rather than a few days, and the subject was on the hook for their own alternative mode of transportation during that time.