After a bad trip into the underworld of wreckers, storage lots and repair shops, you might think the accident was the best part of the experience.

In Houston, that little world is held together by a tangled web of relationships between wrecker drivers, storage lots and repair shops. "There are," says one critical observer, "kickbacks all the way down the chain." Those in the business prefer to call them "finder's fees" or "commissions." And as much as customers might be upset by what they encounter, there's nothing at all illegal about the arrangements -- which ensures that this hidden world can continue to spin happily in its own well-greased grooves.

And as Promila Kohli found out, there's not a whole lot someone who thinks she's been wronged can do about it. Kohli eventually hired a lawyer and filed suit against the body shop where her Mazda ended up after her accident; so far, she hasn't recovered a dime.

From a distance, sorting out who's who in the world of wreckers can be confusing.

At the far fringes are repo men, who collect cars that have been repossessed, sometimes, as in Sidi Boubacar Toure's case, for the smallest of unpaid debts. Regulation of those operations is slack, although at a minimum repo towers are required to have a T-tag (for transfer tag), an easily obtainable tow permit issued by the city of Houston that essentially allows the holder to move a vehicle from one place to another, say from a driveway to a repair shop or storage lot.

"They operate at the edge of the law," says one city official familiar with complaints about the repo business. "They almost steal these cars. The police department and the district attorney have been hesitant to take action against them."

Perhaps reflective of the repo man's reputation is the case from last year of a car owner in northeast Houston who shot a tow-truck driver he saw hitching up his car in his driveway one night. The repo man died from his wounds; the car owner was never charged with a crime.

Higher up the food chain are the holders of the P-tag (for private tag), which allows the holder to transfer vehicles from one spot to another and also permits him to tow a car that's broken down on a roadway or one that's been stolen. The city sets no limit on the number of P-tags and T-tags it can issue; a holder of such a permit only has to apply for one and then meet certain background and insurance requirements.

Then there's the prized E-tag (for emergency tag), which allows a wrecker driver to engage in police-authorized tows, either of vehicles from accident scenes or vehicles whose drivers have been taken into custody. By law, only E-tag holders can make a "non-consent" tow (meaning the driver hasn't given his permission) from an accident scene. The E-tag holder is also limited to charging $57 for the tow, and must take the vehicle to a storage lot authorized to receive police-designated tows. If a motorist is drunk, arrested or injured, the police officer at the scene has the wrecker drivers draw names or discs from a hat to determine who gets to tow the car.

There is an exception: if a driver who's been in an accident is awake, alert and not arrested, he can choose the wrecker company he wants and negotiate the price for a tow to the location of his choice. In such an instance, a P-tag holder can also handle the job.

The city has issued only 236 E-tag permits, at a renewal cost of just $200 a year, with the idea that limiting their number controls congestion at accident scenes and keeps drivers from being victimized by unscrupulous tow merchants. The intent is admirable, but the problem is that once an E-tag is granted, it can be withdrawn only if the holder is convicted of certain crimes, including theft, sexual assault or drug violations. And then there's the problem that the E-tag may not always be used by the person who was granted it (even if the tag holder is ultimately responsible for it). Outside the city's purview, E-tags are considered so valuable that they can change hands on the open market for $30,000 to $50,000, and they're routinely leased by drivers and repair shops for $1,000 to $3,000 a month.

"There's no review process [for E-tags]," explains Ellis Milam, a former police officer who oversees the city of Houston office charged with regulating wreckers, cabs, limousine services and school buses. "Once they have them, they have them."

And having them can be a gold mine. That's because the charge for hitching up a car and hauling it away is only one of the ways to make money in the wrecker business. Some wrecker drivers get a commission from storage lots for transporting cars there; many of the E-tags are held by people in the storage lot business. Storage lots or wrecker drivers that make referrals to body shops can expect a flat commission or a finder's fee from the shop or a percentage of the gross cost of repairs for each vehicle they deliver. A reimbursement of from 1 percent to 8 percent of a bill -- and in some cases even more -- can mean hundreds of extra dollars, depending on the extent of the repairs. That helps explain why the competition for business among wrecker drivers -- a competition familiar to Houston motorists who've had the unnerving experience of being between a speeding wrecker and an accident -- is so fierce, and why on occasion fisticuffs and verbal altercations erupt between rival drivers at accident scenes.