Looking at the 24 hours of lemons, I wondered; are there any stock cars out there that don t require an additional roll cage?Volvo maybe?
Some cars such as the Audi R8 and some Porsche models are designed with racing in mind and can be exempted from requiring safety cages by some racing authorities. They still need other mods though. I have no idea whether they’d be exempt from using safety cages for racing at Le Mans, but as neither of those cars are in your price bracket and you aren’t racing at Le Mans the simple answer to your question is “No”. You will need a safety cage because an item known to be designed to be strong all round trumps a car which has only been designed to pass statutory crash tests from specific angles. Real life and racing don’t fit those rules.
Get some pipe and weld up your own from scratch