Expected correlations? (Score 1)

Without wanting to sound predudiced against either elderly people or Toyota, it's probably reasonable to say that as a sample of the population of "all drivers", drivers of Toyotas will be skewed towards the older end of the age range. You certainly wouldn't conduct an estimate of the average age of the population based purely on the drivers of one particular make of car, whatever it was, due to the very high likelihood of such a bias.

Given that reaction time does increase with age, it's again not unreasonable to expect that the occurence of incidents in which reaction time is likely to be a factor would show some correlation with age.

I think it's also reasonable to expect that in the case of an accelerator being stuck 'on', any resulting accidents are more likely to happen at low speeds than at high speeds. On a typical motorway / highway if your car suddenly went to full throttle then you would generally have more time to react, and more space to bring the car to a safe stop. The effect of going full throttle at, say, 70mph in a high gear is also much less dramatic than at 5mph in 1st gear. When maneouvering or driving at low speed there is a very high likelihood of there being traffic, buildings, trees etc around - hence the low speed in the first place.