The best Cerbera to go for is the Speed Six, simply because of the engine, the Cerbera 4.2 and Cerbera 4.5's use AJP8 engines, very powerful, very fast, very high maintenence and very expensive to repair (though the 4.5 Red rose might be worth the extra costs). the AJP6 enigne is not only more usable, but it's a lot more reliable as well. Still high maintenence but it's a cheaper and better engine to maintain than the AJP8. Driving any TVR in the wet is near suicidal if you have even a remote problem resiting the urge to blip the throttle. Don't go for the cheapest one you find, and low mileage doesn't mean great condition either. A lot of these cars will have seen track days, a low mileage one may well have been thrashed a lot more than a higher mileage one, the only way to know is to ask the owner and check for signs of the car being driven hard. FSH is a must when buying a TVR, you'll be lucky to get a Cerbera still under any kind of warranty but if you do find one in your price budget make that a priority for checking over, if it has the special 5 star gold warranty that's a massive bonus. On the subject of the trim, you can check for rattly trim but it's likely to rattle, you won't need to do much checking of the bodywork, it's fiberglass so there's no rust, check for any signs of replacement pankes like a replacment front end or bonnet and check for cracks in the bodywork, some may be very fine some may have been touched over with paint, they're signs it's had a shunt. Also check for...
Misaligned gearchange linkages
Warped rear suspension wishbones
Snapped steering-wheel control ribbon cables
Deteriorating rear anti-roll bar mounts
Leaking radiator cores, seizing door hinges
Ineffective crankshaft seals, and shearing clutch release arms
Alternator
Water pump
remote boot operating system
And the alarm system
I hope I haven't put you off
, there is a lot to check and a lot of the mechanicla problems listed apply more to the AJP8 engines rather than the AJP6's. A well looked after Cerbera (AJP6 in particular) will be good in most or perhaps even all of thoes areas. depite the problems, a Cerbera is still far cheaper than buying a permium sportscar with similar or even less performance.