Utah legislators patted themselves on the back only two months ago when they dumped the state's complicated vehicle property-tax system for a flat-fee operation.

But Wednesday, some legislators wondered if, just maybe, what they'd done violated the state constitutional provision of taxing property according to value.And while some people talk about extending the flat-fee system to boats, snowmobiles and other recreational vehicles, others talk about a constitutional amendment - maybe even a special legislative session this summer - to "fix for sure" the car tax that has already passed.

Sen. Howard Stephenson, R-Draper, Wednesday asked legislative attorneys to draft such a constitutional amendment. His motion passed the Revenue and Taxation Interim Committee.

Rep. Greg Curtis, R-Sandy, is worried about even talking about a constitutional amendment. An attorney, Curtis said lawmakers shouldn't be giving any hints to the Utah Supreme Court that maybe the new car fee is unconstitutional.

"We're going about this backasswards," Curtis said. Instead of passing laws and then adopting constitutional amendments to make the laws legal, legislators should pass constitutional amendments first, he said.

In the 1998 session, lawmakers adopted a bill sponsored by Sen. George Mantes, R-Tooele, that junks the ad valorem tax system, based on blue-book value, on cars and imposed a fee based on the age of the car.

While the owners of new, expensive cars may see a $400 tax bill the first year they have the vehicle, under the new plan they pay a maximum of $150. The owners of older cars may see a slight increase in their yearly car taxes/fees. A 12-year-old and older car has a minimum fee of $10. A 9-year-old car carries a yearly fee of $50.

But Mantes told the committee Wednesday that while the change is greatly misunderstood by the public, "over the long haul (of vehicle ownership) people make out much better" financially under the fee system.

Several people appeared before the committee asking that the new vehicle fee system be imposed on boats and off-road vehicles. They are now taxed on value.

David Haun, Weber County assessor, asked that the current property tax on campers - the kind that are carried in the beds of pickup trucks - be repealed.

Haun said since there is no registration of campers, and counties have no way to tracking the tax, "only honest people are paying it."

Yes, if you've been paying a property tax on your camper all these years you've been obeying the law, but you also wouldn't have been caught if you hadn't paid it, said Haun.

The only way county assessors know to send out camper tax notices is to look at who paid the tax the year before. "If you paid in 1996, but you didn't pay in 1997, then we wouldn't know to send you a notice this year," said Haun.

He said there are no estimates of how much money counties are losing over the unpaid camper tax. In Carbon County, only 14 camper owners paid the tax in 1997, he said. And certainly there are more than 14 campers sitting on Carbon County residents' trucks, he added.

He guesses that in big, urban Wasatch Front counties only $500 a year is being collected in tax per county.

But - just like the car tax question - it is unclear if the Utah Constitution will allow lawmakers to end the tax - the desire expressed by committee members Wednesday.

The Constitution says that if a property tax based on value is not used, then a general fee must be used. So without a constitutional change, it's likely some kind of fee must be charged on campers, legislative attorneys said.

Stephenson said it appears to him lawmakers need some kind of constitutional change to get rid of the camper tax - maybe some other kinds of property taxes as well - and to clear up any questions concerning a fee system for car owners.