Hmm - this is rambling into discussion, but a topic was brought up in the last couple of posts I'm a little sensitive about.
On the topic of "test pilots" - I perhaps incorrectly assumed that this meant no joy riders, serious inquiries only, and not "no test drives". I will certainly not buy a used car that the seller will not let me drive. I almost had a seller do this to me once and I almost walked (it was an E34 M5 IIRC).
I don't ask for a test drive until I've thoroughly inspected the car and spoken to the owner about records. I tell the owner to take it out first to make sure that it's warmed up properly. They can tell me whatever they want to tell me about the car and I'll play with the radio, windows, make sure the AC works and is cold etc... (after telling them that I'm just checking these things out). If it still looks good to me I ask for my turn to drive to establish tightness, vibrations, looseness, clutch issues, tracking, whatever. If I'm still really liking it, I'll ask about nearby locations I can travel at major highway speed (up to 120kph or so) and maybe do some decent braking on off ramps looking for blown bushings and vibrations. I'll treat their car with respect but if it's a performance-oriented car I am going to open it up once or twice, but I'll usually tell them what I have in mind before I do it.
Keep in mind that people who are shopping aren't always experts in what they're shopping for. Sure, if you're an E30 fan, you've owned 4 of them before and you're looking for another then YOU know exactly what you're looking for. Someone might be shopping for a "performance sedan" and has been trying E46s, E36s, E60s and has never driven an E39 before yours (random example). The buyer needs to figure out if they even like E39s at all as well as whether yours is the right one for them. This was my situation when I stepped into E34 M5s for the first time.
If everything passes to this point, THEN I say I also want a pre-purchase inspection because as has already been said, you're not going to pick everything up from the driver's seat. But you can pick up an awful lot.
Years ago when helping a friend shop for an E46 at dealerships it was super-easy to pick up on an enthusiast-maintained car over a cluebag's daily beater and we ruled out 8-10 cars before coming back to what ended up being the first one we looked at. Even at dealers I tell them I want to do something similar. If something catches my eye I want to look it over thoroughly, and sometimes even have the sales guy take it out first so I can observe and check things as a passenger. I also mention I want it warmed up before I drive, but I do like to see if there are any problems with the car when cold (hesitation, clutch grabbiness, trouble shifting) too.
If you don't let me drive your car at some point, I presume that you're hiding something and I'm walking. These aren't Lamborghinis or race bikes you're selling - be reasonable. You have every right to deny someone the drive if they prove to be a doofus after talking with them, but stating that your policy is "no test drives" as an absolute isn't going to fly with someone like me. I suppose if the key words sellers are looking for is "pre-purchase inspection" to know I'm serious then perhaps I need to have more words up front with sellers about *MY* buying process.
I'm not paying for 10 pre-purchase inspections because the owners feel they don't need to let me drive their car before buying it. Conversely if, as a seller, the buyer didn't even want to drive my car I'd wonder what was wrong with them. It happened to me once that a gentleman bought a car I was selling from across the country sight unseen, but he called the dealer where I had it serviced, I gave him samples from my ample service records, and I openly discussed details of a collision I had 7 years before selling.
When I sell, which has not been often, I do what I expect as a buyer. I talk and look in detail with them first, go over maintenance records, then I take it out to get it warmed up and show them the basics, then offer them a turn in the driver's seat. Granted I might not bother with this kind of process if I was selling a 10 year old Corolla or something. I only had one buyer that made me a bit nervous on the drive. He wasn't a doofus and he was a serious buyer, but he opened up my Porsche near a residential area - poor judgement but there was no one else on the road and it was dry. Luckily he knocked it off before I had to say anything to him. In this case it was more an issue of police and public perception than me being worried about an incident. Actually that revealed to me how much faster my car felt when one isn't at the controls.