I'd agree w/ the poster above, you may want to redact some of what you wrote. That said are you talking cash, cash? As in it never hits a bank account? You have good enough credit that frankly I wouldn't be surprised if, when financing through a dealer, they never asked for income verification (it would not be a lie to put your cash income down). Albeit it is something you can't offer verification for (not a crime) and could set off some red flags at the IRS (but hey, maybe you are just paid in cash and honestly report all of it to the IRS so not an issue for you).
If the money or some subset of it regularly hits a bank account, then 3 months of bank statements are accepted by a lot of dealers as proof of income verification, you might not even need a co-signer. Dealers hate it because it often mens they have to pay the finance company to take your loan but if you stand your ground they'll do the deal because it is better than not selling a car after all.
