Test days vs track days; cost, where, how?

[wioifoiee]

i'm trying to find information on what track day organisers allow certain types of cars.
i'm currently shopping around for either an SR3 or ideally, a Formula renault, for a track toy, not for racing. But i need to figure out whether i can practically use these types of cars.

The cost of a test day is...quite a lot. - on the MSV test day calendar for next year, for open wheel cars at Donington (my local track) it costs £500 and goes up to £640 in March.

Are there any TDO's that allow open-wheelers? I'd primarily want to use Donington and Bedford, and treat myself to Silverstone once in a while.
Which ones would allow Radicals?

where do all of you test your race cars, on regular track days or dedicated test days?
and with which organisers?

thanks

EDIT: MSV small print for general track days:
Slick cars allowed. Open wheelers No.

Looks like i'll have to just accept that if i want a single seater....£6-700 is the price i'll have to pay to drive it each time! ouch.
anyway, Problem solved.

Edited by wioifoiee on Wednesday 24th November 13:59

Edited by wioifoiee on Wednesday 24th November 14:07