Where does a type specific field go?
The features data should really exist in a separate table.  Normalize your data for maintainability and scalability.  For instance, you could implement something like this:

create table Manf
(
    pkManf int identity(1, 1) not null primary key clustered,
    Name varchar(256) not null
)

create table Car
(
    pkCar int identity(1, 1) not null primary key clustered,
    fkManf int not null foreign key references Manf(pkManf),
    Name varchar(256) not null
)

create table Features
(
    pkFeatures int identity(1, 1) not null primary key clustered,
    fkManf int not null foreign key references Manf(pkManf),
    Name varchar(256) not null
)


Just because you currently only have one manufacturer with a feature that needs to be noted in data, that doesn't mean that's always going to be the case.  It is a very easy SELECT to retrieve all of the cars with a particular feature.

EDIT: To get all Cars with a particular feature, you'd do something like this:

select c.*
from Car c
inner join Manf m
on c.fkManf = m.pkManf
inner join Features f
on f.fkManf = m.pkManf
where f.Name = 'some feature'